Recent ucsc items

Combined effective field theory interpretation of measurements sensitive to quartic gauge boson couplings in pp collisions at s = 13 TeV with the ATLAS detector

Tue, 28 Jul 2026 00:00:00 +0000

A combination of measurements sensitive to anomalous quartic electroweak gauge boson couplings is presented using proton–proton collision data collected by the ATLAS detector at s = 13 TeV at the LHC. Contributing analyses include measurements of vector-boson scattering in numerous final states as well as a tri-boson measurement. The combined measurement is used to constrain anomalous electroweak boson quartic self-couplings that result from dimension-8 operators in the Éboli model using an effective field theory. Results are presented as 68% and 95% confidence level intervals parameterised by one or two Wilson coefficients, both with and without unitarity constraints applied. Theoretical bounds from unitarity and positivity are overlaid where relevant. Confidence intervals obtained from simultaneous profiled fits to all Wilson coefficients are also presented.

Search for electroweak tt¯Wj production in multileptonic final states at s=13 TeV with the ATLAS detector and bounds on effective field theory operators

Tue, 28 Jul 2026 00:00:00 +0000

A search is presented for the electroweak production of a top-quark pair in association with a boson and at least one additional jet known as the process. This process has embedded within it a -scattering vertex, which is probed directly for the first time. The collision data were collected with the ATLAS detector during Run 2 of the LHC and correspond to an integrated luminosity of at . The search uses same-charge pairs of electrons and muons together with jets, of which at least one is -tagged. The properties of the most forward jet relative to the rest of the event are used to discriminate the electroweak production process from its strong production counterpart. A measured (expected) 95% CL upper limit on the cross section is set at (230 fb), to be compared with the expected Standard Model (SM) cross section of 47.7 fb. Limits are set on the SM effective field theory (EFT) operators and , which modify the electroweak couplings of the top quark through...

Search for emerging jets in pp collisions at s=13TeV with the ATLAS experiment

Tue, 28 Jul 2026 00:00:00 +0000

A search is presented for emerging jets using 140fb-1$$140~\textrm{fb}^{-1}$$ of proton–proton collision data at s=13TeV$$\sqrt{s} = 13~\textrm{TeV}$$, collected by the ATLAS experiment between 2015 and 2018. The search looks for the existence of a dark sector with symmetries similar to those in quantum chromodynamics. This dark sector is populated with dark quarks, which undergo showering similar to quarks in the Standard Model, leading to a high multiplicity of long-lived dark hadrons within a dark jet. These dark hadrons subsequently decay to Standard Model particles via a new heavy scalar mediating particle ϕ$$\phi $$. This results in jets which contain multiple displaced vertices, known as emerging jets. This analysis targets four-jet topologies, with two emerging jets and two Standard Model jets, resulting from the decay of pair-produced scalar mediators. No significant excess above the Standard Model background is observed. For dark pion proper decay lengths of 20mm$$20~\textrm{mm}$$,...

Combination of Measurements of CP Properties of Higgs Boson Interactions with Vector Bosons Using Proton-Proton Collisions at s=13 TeV with the ATLAS Detector

Tue, 28 Jul 2026 00:00:00 +0000

A combination of measurements of the properties of Higgs boson interactions with electroweak gauge bosons is presented, using of proton-proton collisions at recorded by the ATLAS detector. Results from vector boson fusion , inclusive , and channels are combined. No evidence of violation is observed, and constrains on the -violating operators in the Standard Model effective field theory framework (SMEFT) are set in the Warsaw basis. The results from the combination improve by over 40% on previous individual limits on and, for the first time, simultaneous constraints on three coefficients , , and are set. These limits are the most stringent constraints to date on the relevant Wilson coefficients in the SMEFT framework with minimum model dependence.

Search for Higgs bosons produced in association with a high-energy photon via vector-boson fusion and decaying to a pair of b-quarks in the ATLAS detector

Mon, 27 Jul 2026 00:00:00 +0000

A search for Standard Model Higgs bosons produced in association with a high-energy photon and decaying to b b ¯ is performed using 133 fb − 1 of s = 13 TeV pp collision data collected with the ATLAS detector at the Large Hadron Collider at CERN. The photon requirement reduces the multijet background, and the H → b b ¯ decay is the dominant decay mode. Event selection requirements target events produced by vector-boson fusion, the dominant production mode in this channel. Several improvements enhance the search sensitivity compared to previous measurements. These improvements include better background modelling and characterization, the use of a neural-network classifier, and an updated signal extraction strategy adopting a direct binned-likelihood fit to the classifier output. With these improvements, the Higgs boson signal strength is measured to be 0.2 ± 0.7 relative to the Standard Model prediction. This corresponds to an observed significance of 0.3 standard deviations, compared...

SOF-E: An Energy Efficient Robot for Collaborative Transport and Placement of Mechanical Meta-Material Modules

Thu, 23 Jul 2026 00:00:00 +0000

SOF-E: An Energy Efficient Robot for Collaborative Transport and Placement of Mechanical Meta-Material Modules

Season 1, Week 1 - How long does it take to get an article published?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 1 - How long does it take to get an article published?

Do Tax Credits Increase Heat Pump Adoption?

Tue, 21 Jul 2026 00:00:00 +0000

Economists have long argued that many recipients of clean energy subsidies are likelynon-additional, but there are relatively few empirical studies. This paper uses U.S.monthly shipment data to test whether income tax credits increase heat pump adoption. When the tax credit increased from $300 to $2000 in January 2023, there was no increase in shipments. Then, when the tax credit expired in January 2026, there was no decrease in shipments. This lack of a discernible relationship persists after controllingfor seasonal patterns, energy prices, and housing starts. The evidence suggests thatmost recipients of the $2000 tax credit were non-additional, and would have installeda heat pump even without the subsidy. The paper discusses implications for policydesign, economic efficiency, and cost-effectiveness. Finally, the paper points out thatheat pump shipments continue at a strong pace thus far in 2026 even without the taxcredit, with large benefits for the environment.

Season 1, Week 3 - What are the decision points during the publishing process?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 3 - What are the decision points during the publishing process?

Season 2, Week 2 - Journal vs. Publisher

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 2 - Journal vs. Publisher

Season 2, Week 1 - Where do I even start with publishing an article?

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 1 - Where do I even start with publishing an article?

Season 1, Week 5 - How do I get support for the cost of open access publishing?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 5 - How do I get support for the cost of open access publishing?

Season 1, Week 6 - Can I use this thing in my article without violating copyright? Also, how does it work to include an article in my dissertation?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 6 - Can I use this thing in my article without violating copyright? Also, how does it work to include an article in my dissertation?

Season 2, Week 4 - Can I use AI for my article?

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 4 - Can I use AI for my article?

Season 1, Week 4 - How do I respond to peer reviewers’ comments?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 4 - How do I respond to peer reviewers’ comments?

Season 2, Week 5 - What are my options if my article is rejected?

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 5 - What are my options if my article is rejected?

Season 2, Week 3 - What does being a corresponding author involve?

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 3 - What does being a corresponding author involve?

Season 2, Week 6 - How can I develop a publishing plan for my articles?

Tue, 21 Jul 2026 00:00:00 +0000

Season 2, Week 6 - How can I develop a publishing plan for my articles?

Season 1, Week 2 - How should I choose a journal for my research? Is this a good journal?

Tue, 21 Jul 2026 00:00:00 +0000

Season 1, Week 2 - How should I choose a journal for my research? Is this a good journal?

Are Consumers Myopic? Evidence from New and Used Car Purchases

Mon, 20 Jul 2026 00:00:00 +0000

We investigate whether car buyers are myopic about future fuel costs. We estimate the effect of gasoline prices on short-run equilibrium prices of cars of different fuel economies. We then compare the implied changes in willingness-to-pay to the associated changes in expected future gasoline costs for cars of different fuel economies in order to calculate implicit discount rates. Using different assumptions about annual mileage, survival rates, and demand elasticities, we calculate a range of implicit discount rates similar to the range of interest rates paid by car buyers who borrow. We interpret this as showing little evidence of consumer myopia.

If You Build It, They May Not Come: Willingness to Participate in Managed EV Charging

Mon, 20 Jul 2026 00:00:00 +0000

Despite the importance of program participation for policy, treatment effects are often measured on self-selected samples. We study electric vehicle (EV) managed charging, intended to reduce electric grid strain by optimally allocating charging across EVs. Prior work finds large impacts of managed charging among households who volunteer for an RCT. In contrast, we test managed charging with an experiment including all EVs within a California utility. Enrollment is low even with high incentives, and we can reject even modest intent-to-treat effects on electricity consumption. Managed charging is less effective than previously thought, underscoring the value of population-wide experiments.

Why Did Air Conditioning Adoption Accelerate Faster Than Predicted? Evidence from Mexico

Mon, 20 Jul 2026 00:00:00 +0000

A common theme in the vast literature on climate change is the estimation of models using historical data to make predictions many decades into the future. Although there is a large and growing number of these types of studies, researchers rarely return later to check the accuracy of their predictions. In this paper, we perform such an exercise. In Davis and Gertler (2015), we used household-level microdata from Mexico to predict future air conditioning adoption as a function of income and temperature. Revisiting these predictions with 12 years of additional data, we find that air conditioning in Mexico has accelerated, significantly exceeding our predictions. Neither errors in predicting income growth or rising temperatures, nor migration patterns, nor an overly restrictive model can explain the large prediction gap. Instead, our results point to the failure to account for falling electricity prices and technological changes in air conditioner efficiency as key drivers of...

Competing for (In)attention: Price Discrimination in Residential Electricity Markets

Mon, 20 Jul 2026 00:00:00 +0000

This paper studies the causes and consequences of pricing heterogeneity in markets for residential electricity, a nearly homogeneous good. I uncover adverse efficiency and distributional impacts of competition when consumers face heterogeneous search frictions. I show that consumers pay different prices for electricity in the same market, with low-income households and marginalized communities paying systematically higher electricity prices than their higher-income counterparts. These pricing patterns are consistent with a model of firms price discriminating on search frictions through marketing. Using data from Baltimore, I estimate a structural model that shows that this marketing leads to an annual welfare loss of 14% of industry-wide variable costs. Despite having only slightly larger search frictions, low-income households pay substantially higher prices than high-income households primarily due to lower marketing costs in low-income communities. Auxiliary analyses rule out...

Do Time-of-Use Prices Deliver Energy Savings at the Right Time?

Mon, 20 Jul 2026 00:00:00 +0000

Time-of-use (TOU) electricity prices are increasingly being adopted to reduce consumption during the higher marginal cost afternoon hours. There is ample evidence that TOU rates reduce average consumption during the peak price hours of the day, but it is unknown how these energy savings are distributed across days. Using a unique dataset from households with smart thermostats, we find that adopting TOU rates causes large decreases in peak period AC usage, resulting in energy savings that are concentrated on the hottest, highest demand days when the benefits of conservation are the greatest.

Understanding Support for Cost-Ineffective Environmental Policy Instruments

Mon, 20 Jul 2026 00:00:00 +0000

Many governments use environmental standards rather than more cost-effective market-based instruments like pollution taxes or cap-and-trade markets. Using a nationally representative survey experiment, we study whether and why limited understanding of economic principles helps explain this practice. Holding environmental impacts constant, respondents prefer standards over market-based instruments, and prefer producer taxes and cap-and-trade over consumer taxes. These preferences reflect consumers’ beliefs about how these policies will affect electricity bills. Respondents also prefer the weakest environmental targets for consumer taxes and the strongest targets for standards, which suggests that policymakers face a tradeoff between policy stringency and cost effectiveness. A separate survey of environmental economists shows that they have strikingly different beliefs about the effects of environmental policies than the respondents in our representative survey. For example,...

Effects of the Proposed New California SAF Tax Credit

Mon, 20 Jul 2026 00:00:00 +0000

In Wu et al. (2025), we developed a detailed partial equilibrium model of road and air transportation fuel markets to compare policy options to incentivize the deployment of sustainable aviation fuel (SAF). We used the model to examine policy options for meeting a 3 billion gallon annual SAF target by 2030, which would result in SAF comprising about 12% of U.S. jet fuel consumption in that year. This goal, whether formally adopted or not, represents a useful near-term benchmark along a meaningful path toward decarbonizing aviation and appears to be feasible from a technological perspective. In this note, we add California’s proposed SAF tax credit to the model and evaluate the effects on fuel prices, volumes and emissions. See Wu et al. (2025) for details on the model.

Profiting from Regulation: An Event Study of the European Carbon Market

Mon, 20 Jul 2026 00:00:00 +0000

We investigate the effect of cap-and-trade regulation on firm profits by performing an event study of the EU CO2 price crash. We examine returns for 124 carbon-intensive stocks and over 400 additional stocks, all from the broad EUROSTOXX index. Despite a reduction in environmental costs, we find that stocks fell for firms in carbon-intensive industries. We find similar effects for firms in electricity-intensive industries. The effects are most pronounced for firms that sell primarily within the EU. Our results imply that investors focus on product price impacts, rather than just compliance costs. We find evidence that firms’ net allowance positions also strongly influenced the share price response to the decline in allowance prices.

The Trouble with Green Subsidies

Mon, 20 Jul 2026 00:00:00 +0000

This paper explores the efficiency consequences of pursuing pollution reduction through a reliance on green subsidies rather than pollution taxes. It presents a stylized model of “subsidy-first” policy in which subsidies are rationalized by missing or incomplete taxes on some goods. It delineates five sources of inefficiency in subsidies, several of which relate to information requirements. In the model, green subsidies are justified because they induce substitution away from dirtier alternatives. Thus, subsidies hinge on counterfactuals, which creates information challenges analogous to the additionality problem. Insights from the model are used to comment on the Inflation Reduction Act.

Groundwater and Crop Choice in the Short and Long Run

Mon, 20 Jul 2026 00:00:00 +0000

How do agents respond to policy when investments have high upfront costs and lasting payoffs? We estimate farmers’ short- and long-run responses to changes in groundwater pumping costs in California—where perennial crops with these features are prevalent, and where groundwater pumps consume 6% of the state’s electricity. We use both fixed effects and dynamic discrete choice models that leverage quasi-experimental variation in agricultural electricity tariffs. In the short run, farmers’ groundwater (electricity) demand elasticity is −0.76 (−0.72), and they do not change crops. In contrast, the long-run groundwater (electricity) elasticity is −0.36 (−0.37), driven in part by meaningful reductions in water intensive perennial cropping. Meeting California’s sustainability targets would require reallocation of 9% of acres, including a 50% increase in fallowing. This would also reduce electricity consumption for this end-use by nearly 20%.

Utilizing Noncoincident Needs to Site Data Centers with Solar+Storage at Existing Gas Plants

Mon, 20 Jul 2026 00:00:00 +0000

Data centers and large electricity loads are power hungry, raising concerns about higher electricity costs, increased emissions, and reliability risks. We show that co-locating solar+storage systems with underutilized natural gas plants offers a practical, near-term pathway for reliable, low-cost industrial power. Using eight years of hourly weather data, we co-optimize load and hybrid solar+storage+gas configurations at 68 existing plants near data center developments, meeting over 95% of demand with solar+storage. Across these sites, levelized costs range from $60-138/MWh, competitive with data centers’ recent contract prices for 24/7 clean power. Conflict analysis indicates minimal overlap between solar+storage backup needs and grid stress across most regions of the United States today, allowing gas units to provide dual roles: facilitating large load integration while supporting grid reliability. By optimizing existing infrastructure, this approach offers a scalable pathway...

Competitive Effects of Entry in Gasoline Markets

Mon, 20 Jul 2026 00:00:00 +0000

We use panel data on the location, prices, and quality of the universe of gas stations in Mexico to study the competitive effects of entry on incumbent firms. Using more than 1,000 entry events and defining local markets based on the road network, we find that the entry of a new station within three minutes driving time decreases regular gasoline prices by 6 percent of the retail price spread. Competitive effects decline with travel time and are largest in markets that previously had only one station. Entry of stations with the same owner as the incumbent has near-zero effects on price. In addition, we find that entry increases the service quality of incumbents, with fewer customer complaints.

Dynamic Grid Management Technologies Reduce Wildfire Adaptation Costs in the Electric Power Sector

Mon, 20 Jul 2026 00:00:00 +0000

Wildfire is among the fastest-growing economic risks of climate change, yet strategies to adapt cost-effectively remain under-explored. In the electric power sector, where ignitions have triggered some of the most destructive wildfires on record, utilities are investing heavily to mitigate risk. This study evaluates the cost, reliability, and risk reduction benefits of the largest utility wildfire mitigation program in the U.S. Using detailed weather and vegetation data for 25,000 miles of high-risk powerlines, we develop a prediction model to estimate ignition risk and compare outcomes across locations with similar risk that received different interventions. With this quasi experimental design, we find that a new strategy that dynamically adjusts protective device sensitivity during elevated wildfire conditions reduces risk more cost-effectively than conventional measures such as burying powerlines underground or trimming vegetation. By combining models of wildfire risk, costs,...

Does Regulation Distort Exit Decisions? Evidence from U.S. Power Plants

Mon, 20 Jul 2026 00:00:00 +0000

Hundreds of power plants have closed in the United States since 2010, including 130+ gigawatts of coal and 50+ gigawatts of natural gas. In this paper, we highlight the potential for regulation to distort this type of exit decision. Using generator-level data from 2010–2023, we show that regulated units have been 45% less likely to exit than unregulated units. For unregulated units, exit decisions are made based on wholesale electricity prices, ongoing capital costs, and other traditional economic factors. In contrast, owners of regulated units are largely insulated from these factors and, in some cases, have a strong incentive to continue operating capital-intensive equipment. Previous work documents how this regulatory distortion affects investment decisions. Our paper emphasizes that these same incentives affect exit decisions as well.

The Distributional Effects of U.S. Tax Credits for Heat Pumps, Solar Panels, and Electric Vehicles

Mon, 20 Jul 2026 00:00:00 +0000

U.S. households have received over $47 billion in tax credits since 2006 for heat pumps, solar panels, electric vehicles, and other “clean energy” technologies. Using information from tax returns, we show that these tax credits have gone predominantly to higher-income filers. The bottom three income quintiles have received about 10% of all credits, while the top quintile has received about 60%. The most extreme is the tax credit for electric vehicles, for which the top quintile has received more than 80%. These patterns have changed little over time. We then present evidence on cost effectiveness and discuss broader economic considerations.

Deep Learning Projects Jurisdiction of New and Proposed Clean Water Act Regulation

Mon, 20 Jul 2026 00:00:00 +0000

Projecting the effects of proposed policy reforms is challenging because no outcome data exist for regulations that governments have not yet implemented. We propose an ex ante deep learning framework that can project effects of proposed reforms by mapping outcomes observed under past regulations onto the legal criteria of proposed future policies (i.e., by “relabeling”). We apply this framework to study changes in jurisdiction of the US Clean Water Act (CWA), which regulates many sites used for renewable and fossil energy, transmission lines and pipelines, transportation infrastructure, and other types of land use. We compare our ex ante deep learning projection of jurisdiction under the Supreme Court’s Sackett decision against widely used projections from domain experts. Ex ante machine learning generates exceptional performance improvements over the leading domain expert model that the US Environmental Protection Agency currently uses, with 65 times more accurate identification...

Machine Learning Predicts Which Rivers, Streams, and Wetlands the Clean Water Act Regulates

Mon, 20 Jul 2026 00:00:00 +0000

We assess which waters the Clean Water Act protects and how Supreme Court and White House rules change this regulation. We train a deep learning model using aerial imagery and geophysical data to predict 150,000 jurisdictional determinations from the Army Corps of Engineers, each deciding regulation for one water resource. Under a 2006 Supreme Court ruling, the Clean Water Act protects two-thirds of US streams and over half of wetlands; under a 2020 White House rule, it protects under half of streams and a fourth of wetlands, implying deregulation of 690,000 stream miles, 35 million wetland acres, and 30% of waters around drinking water sources. Our framework can support permitting, policy design, and use of machine learning in regulatory implementation problems.

The Environmental Costs and Geography of U.S. Data Center Expansion

Mon, 20 Jul 2026 00:00:00 +0000

Data centers powering artificial intelligence are growing rapidly across the United States, raising concerns among policymakers and local communities about their environmental and social costs. These costs depend on where data centers locate, and strategic siting has been proposed as a way to limit them. Using a comprehensive facility-level dataset of past, operational, and announced U.S. data centers, we characterize how the environmental and community characteristics of data center locations evolve over 2010–2030. We quantify how much of the projected growth in environmental damages can be attributed to changes in data center locations versus growth in power requirements. Decomposing projected carbon emissions and monetized local air pollution damages into scale and location-driven composition effects, we find that over 2010–2025, composition changes reduced carbon and local air pollution damages by 4 and 12%, respectively. Over 2024–2030, scale accounts for approximately 97%...

The Effects of “Buy American”: Electric Vehicles and the Inflation Reduction Act

Mon, 20 Jul 2026 00:00:00 +0000

We provide the first ex post microeconomic welfare analysis of the electric vehicle (EV) tax credits in the Inflation Reduction Act (IRA). Relative to pre-IRA policy, the credits generated $1.96 in domestic benefits per dollar of government spending, with taxpayer cost of $36,500 per additional EV. Relative to having no EV credits, they yielded $1.11 in domestic benefits per dollar of government spending. A leasing loophole that sidestepped domestic content rules created negative domestic benefits. A prominent example of green industrial policy, the credits harmed foreign countries by shifting surplus to domestic producers and helped them by decreasing CO2 emissions.

Benefits, Costs, and Distributional Outcomes in an Environmental Market

Mon, 20 Jul 2026 00:00:00 +0000

We study the benefits, abatement costs, and distributional outcomes of the EPA’s NOx Budget Program, a seasonal cap-and-trade market for NOx emissions. Using a new empirical approach, we recover source-specific marginal abatement cost curves and combine them with source-specific air pollution damages to quantify market outcomes. We find that abatement costs under the market are roughly one-sixth those of an abatement-equivalent non-market policy. Despite these large differences in aggregate costs, the market and the non-market policy yield similar air quality benefits, both in overall magnitude and across demographic groups. We show that these results reflect the weak correlation between source-specific marginal damages and abatement behavior.

Can Vertically Integrated Firms Evade Pricing Regulation? Evidence from Energy Utilities

Mon, 20 Jul 2026 00:00:00 +0000

Vertical mergers can be used by a natural monopoly subject to cost-based price regulation to evade regulation: when regulators allow increases in input costs to be passed onto customers, a monopolist that is vertically integrated with an input supplier can earn profits by inflating input costs. I test for evidence of evasion by US electric and natural gas utilities through their purchase of interstate natural gas pipeline capacity. Building a novel data set of the vertical relationships of natural gas pipelines, I find incentives for evasion are widespread in this industry: 53% of US households with gas heating purchase gas from a utility that is affiliated with a natural gas pipeline. I leverage variation in buyers’ vertical relationships with pipelines and exposure to regulation to test whether evasion incentives cause buyers to inflate input costs. Results show that evasion incentives lead buyers to inflate costs by overbuilding pipeline capacity: capacity under contract with...

Global Policy Spillovers: How Environmental Policies Propagate through Product Attributes

Mon, 20 Jul 2026 00:00:00 +0000

How should policymakers evaluate policy impacts when firms design products for global mar kets? Standard economic analyses typically focus on domestic outcomes, implicitly assuming that policies affect only the jurisdiction in which they are enacted. Yet multinational firms often harmonize product design across markets, creating the potential for policies implemented in one country to generate global spillovers through changes in product attributes. We call this phenomenon “attribute propagation” and develop a framework to measure and assess its quantitative importance. Applying this framework to an environmental policy affecting auto mobiles, we find that a fuel-economy subsidy in Japan led to significant improvements in the fuel economy of vehicles sold in the United States. We then develop a model of multinational automobile markets featuring cross-market cost complementarity as a key mechanism driving attribute propagation. Using the estimated model, we conduct counterfactual...

How Much Has Shale Gas Saved U.S. Consumers?

Mon, 20 Jul 2026 00:00:00 +0000

It may seem like a distant memory now, but as of the mid-2000s, U.S. natural gas production had been flat for a decade, and the U.S. was importing liquefied natural gas (LNG), with plans to import much more. Then shale gas happened. Advances in hydraulic fracturing and horizontal drilling caused U.S. natural gas production to increase significantly, and the U.S. went from being a net importer of natural gas to being the world’s largest exporter. This paper calculates how much shale gas has saved U.S. natural gas consumers. Using price differences between the United States, Europe and Japan, we calculate that U.S. natural gas consumers have saved $3.1-$4.3 trillion between 2007 and 2025, equivalent to $164-$227 billion annually. Access to low-price U.S. natural gas has been particularly valuable during major supply shocks such as the war in Ukraine, and the benefits of shale gas have been experienced broadly across sectors and states.

Solar Tachocline Confinement by the Nonaxisymmetric Modes of a Dynamo Magnetic Field

Fri, 17 Jul 2026 00:00:00 +0000

We recently presented the first 3D numerical simulation of the solar interior for which tachocline confinement was achieved by a dynamo-generated magnetic field. In this follow-up study, we analyze the degree of confinement as the magnetic field strength changes (controlled by varying the magnetic Prandtl number) in a coupled radiative zone (RZ) and convection zone (CZ) system. We broadly find three solution regimes, corresponding to weak, medium, and strong dynamo magnetic field strengths. In the weak-field regime, the large-scale magnetic field is mostly axisymmetric with regular, periodic polarity reversals (reminiscent of the observed solar cycle) but fails to create a confined tachocline. In the strong-field regime, the large-scale field is mostly nonaxisymmetric with irregular, quasi-periodic polarity reversals and creates a confined tachocline. In the medium-field regime, the large-scale field resembles a strong-field dynamo for extended intervals but intermittently weakens...

Delayed structural prediction for relative clauses: A new argument for learning to parse from Santiago Laxopa Zapotec

Fri, 17 Jul 2026 00:00:00 +0000

Comprehenders in many of the world's languages exhibit a preference or a greater ease in comprehending transitive relative clauses (RCs) when associating the dislocated head with a subject position. Some theories relate this preference to an early prediction that an animate head will serve as a subject. We present a picture selection experiment with eye-tracking investigating the role of such predictions in comprehending transitive RCs in Santiago Laxopa Zapotec, an Oto-Manguean language of southern Mexico where RCs are ambiguous unless they contain a resumptive pronoun. Patterns of offline choices and incremental looking suggest that Santiago Laxopa Zapotec comprehenders avoid forming predictive interpretations of the RC head, and do not take its animacy into account in early processing. Instead, comprehenders exhibit a later, animacy-sensitive bias to interpret the RC-internal co-argument as a subject. Overall, we take this pattern as evidence that a comprehender's structural...

The Role of Downflows in Establishing Solar Near-surface Shear

Fri, 17 Jul 2026 00:00:00 +0000

The dynamical origins of the Sun’s tachocline and near-surface shear layer (NSSL) are still not well understood. We have attempted to self-consistently reproduce an NSSL in numerical simulations of a solar-like convection zone by increasing the density contrast across rotating 3D spherical shells. We explore the hypothesis that high density contrast leads to near-surface shear by creating a rotationally unconstrained layer of fast flows near the outer surface. Although our high-contrast models do have near-surface shear, it is confined primarily to low latitudes (between ±15°). Two distinct types of flow structures maintain the shear dynamically: rotationally constrained Busse columns aligned with the rotation axis and fast, rotationally unconstrained downflow plumes that deplete angular momentum from the outer fluid layers. The plumes form at all latitudes and, in fact, are more efficient at transporting angular momentum inward at high latitudes. The presence of Busse columns...

Confinement of the Solar Tachocline by Dynamo Action in the Radiative Interior

Fri, 17 Jul 2026 00:00:00 +0000

A major outstanding problem in solar physics is the confinement of the solar tachocline, the thin shear layer that separates nearly solid-body rotation in the radiative interior from strong differential rotation in the convection zone. Here, we present the first 3D, global solar simulation that displays a magnetically confined tachocline. The nonaxisymmetric magnetism is initially built in the convection zone and then diffusively imprints downward, similar to the proposed fast magnetic confinement scenario by the Sun’s cyclic dynamo field. Additionally, the field is locally amplified throughout the radiative interior by vigorous horizontal motions that seem to arise from a combination of equatorial Rossby waves and shear, magnetic, and buoyancy instabilities. Our work thus supports prior studies proposing dynamo action in the radiative interior, and suggests that horizontal motions could play a key role in driving this deep dynamo.

A Dynamo Confinement Scenario for the Solar Tachocline and Its Implications for Spin-down in the Radiative Spreading Regime

Fri, 17 Jul 2026 00:00:00 +0000

At the base of the Sun’s convective zone, a narrow shear layer called the tachocline separates strong latitudinal differential rotation above from nearly rigid rotation in the radiative zone below. The observed thinness of the tachocline is a long-standing dynamical puzzle because the tachocline should have spread significantly due to inward-burrowing meridional circulation, also called “radiative spreading.” We recently presented the first pair of global simulations to reveal a statistically stationary tachocline confined against radiative spreading by the Maxwell stresses from the large-scale nonaxisymmetric modes of a dynamo, which penetrated into and below the tachocline through a novel magnetic skin effect. In the work presented here, we systematically examine how this “dynamo confinement scenario” works against radiative spreading in a suite of simulations as the governing parameters trend in the direction of the true solar regime. We find that as the stable stratification...

Revisiting the Sun’s Strong Differential Rotation along Radial Lines

Fri, 17 Jul 2026 00:00:00 +0000

Current state-of-the-art models of the solar convection zone consist of solutions to the Navier–Stokes equations in rotating, 3D spherical shells. Such models are highly sensitive to the choice of boundary conditions. Here we present two suites of simulations differing only in their outer thermal boundary condition, which is either one of fixed entropy (FE) or fixed flux (FF; corresponding to a fixed gradient in the entropy). We find that the resulting differential rotation is markedly different between the two sets. The FF simulations have strong differential rotation contrast and isocontours tilted along radial lines (in good agreement with the Sun’s interior rotation revealed by helioseismology), whereas the FE simulations have weaker contrast and contours tilted in the opposite sense. We examine in detail the force balances in our models and find that the poleward transport of heat by Busse columns drives a thermal wind responsible for the different rotation profiles. We conclude...

Toward a Self-consistent Hydrodynamical Model of the Solar Tachocline

Fri, 17 Jul 2026 00:00:00 +0000

The solar tachocline is a thin internal boundary layer in the Sun located between the differentially rotating convection zone and the uniformly rotating region of the radiative interior beneath. E. A. Spiegel & J. P. Zahn proposed the first hydrodynamical model, which here we call SZ92, arguing that the tachocline is essentially in a steady state of thermal-wind balance, angular-momentum balance, and thermal equilibrium. Angular momentum transport in their model is assumed to be dominated by strongly anisotropic turbulence, which is primarily horizontal, owing to the strong stable stratification of the radiative interior. By contrast, the heat transport is assumed to be dominated by a predominantly vertical diffusive heat flux, owing to the thinness of the tachocline. In this paper, we demonstrate that these assumptions are not consistent with the new model of stratified turbulence recently proposed by G. P. Chini et al. and K. Shah et al., which has been numerically validated...

Inertial Waves in a Nonlinear Simulation of the Sun's Convection Zone and Radiative Interior

Fri, 17 Jul 2026 00:00:00 +0000

Recent observations of Rossby waves and other more exotic forms of inertial oscillations in the Sun’s convection zone have kindled the hope that such waves might be used as a seismic probe of the Sun's interior. Here, we present a 3D numerical simulation in spherical geometry that models the Sun’s convection zone and upper radiative interior. This model features a wide variety of inertial oscillations, including both sectoral and tesseral equatorial Rossby waves, retrograde mixed inertial modes, prograde thermal Rossby waves, the recently observed high-frequency retrograde (HFR) vorticity modes, and what may be latitudinal overtones of these HFR modes. With this model, we demonstrate that sectoral and tesseral Rossby waves are ubiquitous within the radiative interior as well as within the convection zone. We suggest that there are two different Rossby-wave families in this simulation that live in different wave cavities: one in the radiative interior and one in the convection...

Exploring Bistability in the Cycles of the Solar Dynamo through Global Simulations

Fri, 17 Jul 2026 00:00:00 +0000

The calling card of solar magnetism is the sunspot cycle, during which sunspots regularly reverse their polarity sense every 11 yr. However, a number of more complicated time-dependent behaviors have also been identified. In particular, there are temporal modulations associated with active longitudes and hemispheric asymmetry, when sunspots appear at certain solar longitudes or else in one hemisphere preferentially. So far, a direct link between this asymmetric temporal behavior and the underlying solar dynamo has remained elusive. In this work, we present results from global 3D magnetohydrodynamic simulations, which display both behavior reminiscent of the sunspot cycle (regular polarity reversals and equatorward migration of internal magnetic field) and asymmetric, irregular behavior which we interpret as active longitudes and hemispheric asymmetry in the simulations. The simulations are thus bistable, in that the turbulent convection can stably support two distinct flavors...

The Puzzling Structure of Solar Convection: Window into the Dynamo

Fri, 17 Jul 2026 00:00:00 +0000

The Puzzling Structure of Solar Convection: Window into the Dynamo

An End-to-End Pipeline to Generate Augmented Tactile Maps from Floor Plans

Fri, 17 Jul 2026 00:00:00 +0000

An End-to-End Pipeline to Generate Augmented Tactile Maps from Floor Plans

Protecting OSPF Against Cyber Attacks by Sharing a Few Large Integers Among Routers

Fri, 17 Jul 2026 00:00:00 +0000

Protecting OSPF Against Cyber Attacks by Sharing a Few Large Integers Among Routers

A Cross-Layer Protocol for Decentralized Structured Nonorthogonal Access

Fri, 17 Jul 2026 00:00:00 +0000

A Cross-Layer Protocol for Decentralized Structured Nonorthogonal Access

Measurement of the W-boson angular coefficients and transverse momentum in pp collisions at s=13 TeV with the ATLAS detector

Thu, 16 Jul 2026 00:00:00 +0000

The angular distributions of Drell–Yan lepton pairs provide sensitive probes of the underlying dynamics of quantum chromodynamics (QCD) effects in vector-boson production. This paper presents for the first time the measurement of the full set of angular coefficients together with the differential cross-section as a function of the transverse momentum of the W boson, in the full phase space of the decay leptons. The measurements are performed separately for the W-$$W^-$$ and W+$$W^+$$ channels. The analysis uses proton–proton collision data recorded by the ATLAS experiment at the Large Hadron Collider in 2017 and 2018, during special low-luminosity runs with a reduced number of interactions per bunch crossings (pile-up). The data correspond to an integrated luminosity of 338 pb-1$$^{-1}$$ at a centre-of-mass energy of s=13$$\sqrt{s} = 13$$ TeV. The low pile-up environment provides excellent experimental conditions for high-precision measurements of W-boson production....

A genome assembly of the speckled dace, Rhinichthys osculus

Thu, 16 Jul 2026 00:00:00 +0000

The speckled dace, Rhinichtyhs osculus, is a cyprinoid fish species complex (family: Leuciscidae) with one of the widest native ranges of any freshwater fish in western North America. It occupies a variety of freshwater habitats and exhibits considerable morphological and genetic variation across its range. Several endemic taxa within the species complex are imperiled, four of which are protected under the US Endangered Species Act, with two more proposed for listing. Here, we present an annotated, scaffold-level assembly of the speckled dace genome as part of the California Conservation Genomics Project (CCGP). Consistent with the CCGP genome assembly strategy, we used Pacific Biosciences HiFi long reads and Omni-C data for our de novo genome assembly and performed genome annotations on NCBI Eukaryotic Genome Annotation Pipeline using novel, species-specific RNA-Seq reads generated from five tissue types. The assembly consists of 490 scaffolds totaling approximately 1.15 Gb,...

Search for the Higgs boson decay to a Z boson and a photon in pp collisions at s = 13 TeV and 13.6 TeV with the ATLAS detector

Thu, 16 Jul 2026 00:00:00 +0000

A search for the Higgs boson decay to a Z boson and a photon in the ℓℓγ ( ℓ = e , μ ) final state is performed using pp collisions at s = 13.6 TeV recorded with the ATLAS detector at the Large Hadron Collider during 2022–2024, corresponding to an integrated luminosity of 165 fb − 1 . The signal yield, normalised to the Standard Model prediction, is measured to be μ = 0 . 9 − 0.6 + 0.7 , compatible with the expected value of μ = 1.0 ± 0.7 . This corresponds to an observed (expected) signal significance of 1.4 (1.5) standard deviations under the background-only hypothesis. This result is combined with that of a similar search performed with 140 fb − 1 of s = 13 TeV pp collisions to provide the best expected sensitivity to date to this rare decay, namely an observed (expected) signal strength of μ = 1 . 3 − 0.5 + 0.6 ( μ = 1 . 0 − 0.5 + 0.6 ), corresponding to an observed (expected) significance of 2.5 (1.9) standard deviations. The measurement is consistent with the Standard Model...

Ammonia and nitrite oxidation in the upper euphotic zone of the oligotrophic Red Sea

Thu, 16 Jul 2026 00:00:00 +0000

Abstract. Nitrification is widely understood to be inhibited by light in the surface ocean, however, increasing evidence indicates its occurrence at low levels at many sites. The extent to which nitrification remains active in the euphotic zone could have important implications to new production calculations, yet it remains understudied. Here, we quantified ammonia and nitrite oxidation rates in the euphotic zone of the Gulf of Aqaba (Northern Red Sea) from late spring to late summer and examined environmental controls and implications for dark carbon fixation (chemoautotrophy) and new production. Both ammonia and nitrite oxidation were detectable throughout the euphotic zone (∼ 0.1–0.8 nmolNL-1d-1). Overall, rates were low in the highest-irradiance surface waters and increased with depth. Integrated rates over the entire euphotic zone (24–56 µmolNm-2d-1) were among the lowest reported for oligotrophic regions globally. This reflects extremely low substrate concentrations and...

The genome assemblies of the Tui chub, Siphateles bicolor, and Arroyo chub, Gila orcuttii

Thu, 16 Jul 2026 00:00:00 +0000

We present genome assemblies for two cyprinoid fishes, the tui chub (Siphateles bicolor) and the arroyo chub (Gila orcuttii). These fishes are ecologically important representatives of native fish assemblages in the western United States and are both species of conservation concern. The two species hybridize where introductions bring them into contact, with potentially important ecological and evolutionary implications that have not yet been thoroughly examined from a genomic perspective. We present de novo assemblies for both species, representing the first scaffold-level genomes within their respective genera, which were developed as part of the California Conservation Genomics Project using Pacific Biosciences HiFi and Omni-C data. Our tui chub assembly consists of 258 scaffolds spanning 1,148,084,093 base pairs, has a scaffold N50 of 45.9 mb, a contig N50 of 23.7 mb, and a BUSCO completeness score of 98.1%. Our arroyo chub assembly consists of 179 scaffolds spanning...

Study of Higgs boson pair production in the H H → b b ‾ γ γ final state with 308 fb − 1 of data collected at s = 13 TeV and 13.6 TeV by the ATLAS experiment

Thu, 16 Jul 2026 00:00:00 +0000

A search for Higgs boson pair production in the b b ¯ γ γ final state is performed. The proton–proton collision dataset corresponds to an integrated luminosity of 308 fb − 1 , consisting of two samples, 140 fb − 1 at a centre-of-mass energy of s = 13 TeV and 168 fb − 1 at s = 13.6 TeV , recorded between 2015 and 2024 by the ATLAS detector at the CERN Large Hadron Collider. In addition to a larger dataset, this analysis improves upon the previous search in the same final state through several methodological and technical developments. The Higgs boson pair production cross section divided by the Standard Model prediction is found to be μ H H = 0 . 9 − 1.1 + 1.4 ( μ H H = 1 − 1.0 + 1.3 expected), which translates into a 95% confidence-level upper limit of μHH  < 3.7. At the same confidence level the Higgs self-coupling modifier is constrained to be in the range − 1.6 < κ λ < 6.6 ( − 1.8 < κ λ < 6.9 expected).

Ecological differences among hydrothermal vent symbioses may drive contrasting patterns of symbiont population differentiation

Thu, 16 Jul 2026 00:00:00 +0000

The intra-host composition of horizontally transmitted microbial symbionts can vary across host populations due to interactive effects of host genetics, environmental, and geographic factors. While adaptation to local habitat conditions can drive geographic subdivision of symbiont strains, it is unknown how differences in ecological characteristics among host-symbiont associations influence the genomic structure of symbiont populations. To address this question, we sequenced metagenomes of different populations of the deep-sea mussel Bathymodiolus septemdierum, which are common at Western Pacific deep-sea hydrothermal vents and show characteristic patterns of niche partitioning with sympatric gastropod symbioses. Bathymodiolus septemdierum lives in close symbiotic relationship with sulfur-oxidizing chemosynthetic bacteria but supplements its symbiotrophic diet through filter-feeding, enabling it to occupy ecological niches with little exposure to geochemical reductants....

Estimating Causal Mediation Effects Under Observed and Unobserved Mediation Effect Heterogeneity

Thu, 16 Jul 2026 00:00:00 +0000

When a treatment operates through an indirect pathway by influencing a mediator, it is plausible that individuals differ in the magnitude or even the presence of mediation effects they experience. Despite this, standard practice in causal mediation analysis is to marginalize over individual-level mediation effects, typically assuming no effect heterogeneity or only coarse differences across observed groups. In this paper, we examine how mediation effects may vary across both observed groups and unobserved subpopulations and assess the consequences of misspecifying this heterogeneity. Using a simulation study, we evaluate the performance of two existing causal mediation approaches and demonstrate how mediation effect estimates can be misleading when the underlying heterogeneity structure is ignored or incorrectly modeled. Our results show that failing to account for mediation effect heterogeneity can lead to substantial bias, with estimated mediation effects that are not simple...

Diverse genetic conflicts mediated by molecular mimicry and computational approaches to detect them

Thu, 16 Jul 2026 00:00:00 +0000

In genetic conflicts between intergenomic and selfish elements, driver and killer elements achieve biased survival, replication, or transmission over sensitive and targeted elements through a wide range of molecular mechanisms, including mimicry. Driving mechanisms manifest at all organismal levels, from the biased propagation of individual genes, as demonstrated by transposable elements, to the biased transmission of genomes, as illustrated by viruses, to the biased transmission of cell lineages, as in cancer. Targeted genomes are vulnerable to molecular mimicry through the conserved motifs they use for their own signaling and regulation. Mimicking these motifs enables an intergenomic or selfish element to control core target processes, and can occur at the sequence, structure, or functional level. Molecular mimicry was first appreciated as an important phenomenon more than twenty years ago. Modern genomics technologies, databases, and machine learning approaches offer tremendous...

Applying evolutionary theory to understand host–microbiome evolution

Thu, 16 Jul 2026 00:00:00 +0000

All plants and animals are host to a community of microorganisms, their microbiotas, which have crucial influences on the life history and performance of their hosts. Despite the importance of such host–microbiota relationships, relatively little is known about the role microbiotas have in mediating evolution of the host and entire host–microbe assemblages. This knowledge gap is partly due to the lack of theoretical frameworks that generate testable predictions on the evolutionary dynamics of host–microbiota systems. In this Perspective, we argue that the foundation for such frameworks exists in evolutionary theory. We highlight four examples of theoretical models—niche construction, indirect genetic effects, maternal effects and multilevel selection—that capture important aspects of host–microbiome evolution. We outline how each of these frameworks can provide key insights into the evolution of host–microbiota systems while also suggesting expansions of current theory to incorporate...

Measurement of differential t-channel single top (anti)quark production cross-sections at 13 TeV with the ATLAS detector

Thu, 16 Jul 2026 00:00:00 +0000

The production of single top quarks and top antiquarks via the t-channel exchange of a virtual W boson is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider. The full Run 2 data sample recorded with the ATLAS detector in the years 2015–2018 is used, corresponding to an integrated luminosity of 140 fb−1. The absolute and normalised production cross-sections are measured differentially as a function of the transverse momentum and absolute rapidity of the top quark and top antiquark. In addition, the ratio of top quark to top antiquark production cross-sections is measured. The measured distributions are compared with next-to-leading-order quantum chromodynamics predictions obtained with different combinations of matrix-element generators, parton-shower programs and proton parton distribution functions, as well as to next-to-next-to-leading-order calculations. Overall, good agreement is observed between the measurements and the...

Precise measurement of the tt¯ production cross-section and lepton differential distributions in eμ dilepton events from s=13TeVpp collisions with the ATLAS detector

Thu, 16 Jul 2026 00:00:00 +0000

The inclusive top quark pair (tt¯$$t\bar{t}$$) cross-section σtt¯$$\sigma _{t\bar{t}}$$ has been measured in proton–proton collisions at s=13TeV$$\sqrt{s}=13\,\text {TeV}$$, using 140fb-1$$140\,{\text {fb}^{-1}} $$ of data collected by the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge eμ$$e\mu $$ pair and b-tagged jets, the cross-section is measured to be: σtt¯=829.3±1.3(stat)±8.0(syst)±7.3(lumi)±1.9(beam)pb,$$\begin{aligned} \sigma _{t\bar{t}} & = 829.3\pm 1.3\,\mathrm {(stat)}\ \pm 8.0\,\mathrm {(syst)}\ \pm 7.3\,\mathrm {(lumi)}\ \\ & \quad \pm 1.9\,\mathrm {(beam)}\,\textrm{pb}, \end{aligned}$$where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the proton beam energy, giving a total uncertainty of 1.3%. The result is used to determine the top quark pole mass via the dependence of the predicted cross-section on mtpole$${m_{t}^\textrm{pole}}$$,...

The End of Neutrality? LCFS, Technology Neutrality, and Stimulating the Electric Vehicle Market