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Cover page of On Picard groups of blocks of finite groups

On Picard groups of blocks of finite groups

(2020)

We show that the subgroup of the Picard group of a $p$-block of a finite group given by bimodules with endopermutation sources modulo the automorphism group of a source algebra is determined locally in terms of the fusion system on a defect group. We show that the Picard group of a block over the a complete discrete valuation ring ${\mathcal O}$ of characteristic zero with an algebraic closure $k$ of ${\mathbb F}_p$ as residue field is a colimit of finite Picard groups of blocks over $p$-adic subrings of ${\mathcal O}$. We apply the results to blocks with an abelian defect group and Frobenius inertial quotient, and specialise this further to blocks with cyclic or Klein four defect groups.

Cover page of DES16C3cje: A low-luminosity, long-lived supernova

DES16C3cje: A low-luminosity, long-lived supernova

(2020)

ABSTRACT We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of ≲1500 km s−1, and the light curve shows an initial peak that fades after 50 d before slowly rebrightening over a further 100 d to reach an absolute brightness of Mr ∼ −15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of 56Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either (i) a low explosion energy (0.11 foe) and relatively large 56Ni production of 0.075 M⊙ from an ∼15 M⊙ red supergiant progenitor typical of other SNe II, or (ii) a relatively compact ∼40 M⊙ star, explosion energy of 1 foe, and 0.08 M⊙ of 56Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼0.5 × 10−8 M⊙ s−1.

Cover page of A Multi-scale Embossed Map Authoring Tool for Indoor Environments

A Multi-scale Embossed Map Authoring Tool for Indoor Environments

(2020)

We introduce a multi-scale embossed map authoring tool (M-EMAT) that produces tactile maps of indoor environments from the building’s structural layout and its 3D-scanned interiors on demand. Our tool renders indoor tactile maps at different spatial scales, representing a building’s structure, a zoomed-in of a specific area, or an interior of a room. M-EMAT is very easy to use and produces accurate results even in the case of complex building layouts.

Cover page of Hemispheric Indigeneities (Review)

Hemispheric Indigeneities (Review)

(2020)

This is a book review of Hemispheric Indigeneities, a study that sets a series of transnational dialogues on issues pertaining commonalities of Indigenous societies in the Americas (Canada, the U.S. and Latin America).

Cover page of Berber Rule and Abbasid Legitimacy: The Almoravids (434/1042–530/1147)

Berber Rule and Abbasid Legitimacy: The Almoravids (434/1042–530/1147)

(2020)

The Almoravids (al-Murābiṭūn 434-530/1042-1147) were a Saharan Berber tribal federation who conquered the western Maghrib and most of al-Andalus in the second half of the fifth/eleventh century. They were the first indigenous group to unify this part of the Maghrib and the first Maghrib-based empire to conquer al-Andalus. They revolutionized the political structures of both regions through a novel combination of local elements with others adopted from the broader Islamic world. Their strategies for political legitimation, which included the concept of ʿAbbāsid investitutre, illustrate this novel combination.

Cover page of In Memoriam. Ad Futurum

In Memoriam. Ad Futurum

(2020)

The essay offers a reflection on memories of traumatic histories, including African American slavery, Native American genocide, and the Holocaust. I weave personal memories together with a consideration of poetry, monuments, and other representations that sometimes tend to efface, sometimes come to grips, as best they can, with these appalling events and their legacies.

Cover page of Test of CP invariance in vector-boson fusion production of the Higgs boson in the H → ττ channel in proton–proton collisions at [Formula presented] with the ATLAS detector

Test of CP invariance in vector-boson fusion production of the Higgs boson in the H → ττ channel in proton–proton collisions at [Formula presented] with the ATLAS detector

(2020)

© 2020 The Author(s) A test of CP invariance in Higgs boson production via vector-boson fusion is performed in the H→ττ decay channel. This test uses the Optimal Observable method and is carried out using 36.1fb−1 of s=13TeV proton–proton collision data collected by the ATLAS experiment at the LHC. Contributions from CP-violating interactions between the Higgs boson and electroweak gauge bosons are described by an effective field theory, in which the parameter d˜ governs the strength of CP violation. No sign of CP violation is observed in the distributions of the Optimal Observable, and d˜ is constrained to the interval [−0.090, 0.035] at the 68% confidence level (CL), compared to an expected interval of d˜∈[−0.035,0.033] based upon the Standard Model prediction. No constraints can be set on d˜ at 95% CL, while an expected 95% CL interval of d˜∈[−0.21,0.15] for the Standard Model hypothesis was expected.