Higher Gauge Theory and Gravity in (2+1) Dimensions

Non-abelian higher gauge theory has recently emerged as a generalization of standard gauge theory to higher dimensional (2-dimensional in the present context) connection forms, and as such, it has been successfully applied to the non-abelian generalizations of the Yang-Mills theory and 2-form electrodynamics. (2+1)-dimensional gravity, on the other hand, has been a fertile testing ground for many concepts related to classical and quantum gravity, and it is therefore only natural to investigate whether we can find an application of higher gauge theory in this latter context. In the present paper we investigate the possibility of applying the formalism of higher gauge theory to gravity in (2+1) dimensions, and we show that a nontrivial model of (2+1)-dimensional gravity coupled to scalar and tensorial matter fields - the $\Sigma\Phi EA$ model - can be formulated both as a standard gauge theory and as a higher gauge theory. Since the model has a very rich structure - it admits as solutions black-hole BTZ-like geometries, particle-like geometries as well as Robertson-Friedman-Walker cosmological-like expanding geometries - this opens a wide perspective for higher gauge theory to be tested and understood in a relevant gravitational context. Additionally, it offers the possibility of studying gravity in (2+1) dimensions coupled to matter in an entirely new framework.Comment: 22 page

Quantum Memristors

Technology based on memristors, resistors with memory whose resistance depends on the history of the crossing charges, has lately enhanced the classical paradigm of computation with neuromorphic architectures. However, in contrast to the known quantized models of passive circuit elements, such as inductors, capacitors or resistors, the design and realization of a quantum memristor is still missing. Here, we introduce the concept of a quantum memristor as a quantum dissipative device, whose decoherence mechanism is controlled by a continuous-measurement feedback scheme, which accounts for the memory. Indeed, we provide numerical simulations showing that memory effects actually persist in the quantum regime. Our quantization method, specifically designed for superconducting circuits, may be extended to other quantum platforms, allowing for memristor-type constructions in different quantum technologies. The proposed quantum memristor is then a building block for neuromorphic quantum computation and quantum simulations of non-Markovian systems

Diversity and Community Pattern of Darkling Beetles (Coleoptera: Tenebrionidae) along an Ecological Gradient in Arid Mongolia

One of the most conspicuous detrito- and phytodetritophagous groups of beetles in the Asian steppes and deserts is the family Tenebrionidae (Coleoptera, Polyphaga) (KONSTANTINOV et al. 2009). Mongolia harbors a rich diversity of these beetles with 215 species and 50 genera of Tenebrionidae listed for the country (MEDVEDEV 1990), many of them restricted to its arid parts, where they obtain high abundances and dominate – together with ants – the insect soil fauna (PFEIFFER et al. 2003). Their dark color may be a means to withstand the high radiation at daytime; however, a large number of species is night active and hide during the day in burrows or under sand. Some of the African species are known to be subsocial and even exhibit division of labor (RASA 1990), but information on the biology of the Asiatic species is scattered and rare. A lot of knowledge on the Tenebrionidae of Mongolia is based on the various expeditions of the famous Hungarian entomologist Dr. Kas zab, who was a taxonomic specialist for these beetles (KASZAB 1965, 1967, 1977). His research was continued by Medvedev (MEDVEDEV & KASZAB 1973, MEDVEDEV & LOBANOV 1990), who developed a key to the Mongolian Tenebrionidae (MEDVEDEV 1990), thus enabling further studies on the ecology of the species. While the community ecology of darkling beetles has been studied in several arid regions of the world (STAPP 1997, BLAUM et al. 2009), especially in Israel (KRASNOV & SHENBROT 1996, 1998) and in the Mediterranean (FATTORINI 2006, 2010), little is known about the central Asian region. SAGDY (1996), investigated community pattern of Tenebrionidae in the Ubsunur Hollow Preserve in Tuva, but nothing is known on the ecological communities of the species rich Mongolian fauna

Diversity and Community Pattern of Darkling Beetles (Coleoptera: Tenebrionidae) along an Ecological Gradient in Arid Mongolia

One of the most conspicuous detrito- and phytodetritophagous groups of beetles in the Asian steppes and deserts is the family Tenebrionidae (Coleoptera, Polyphaga) (KONSTANTINOV et al. 2009). Mongolia harbors a rich diversity of these beetles with 215 species and 50 genera of Tenebrionidae listed for the country (MEDVEDEV 1990), many of them restricted to its arid parts, where they obtain high abundances and dominate – together with ants – the insect soil fauna (PFEIFFER et al. 2003). Their dark color may be a means to withstand the high radiation at daytime; however, a large number of species is night active and hide during the day in burrows or under sand. Some of the African species are known to be subsocial and even exhibit division of labor (RASA 1990), but information on the biology of the Asiatic species is scattered and rare. A lot of knowledge on the Tenebrionidae of Mongolia is based on the various expeditions of the famous Hungarian entomologist Dr. Kas zab, who was a taxonomic specialist for these beetles (KASZAB 1965, 1967, 1977). His research was continued by Medvedev (MEDVEDEV & KASZAB 1973, MEDVEDEV & LOBANOV 1990), who developed a key to the Mongolian Tenebrionidae (MEDVEDEV 1990), thus enabling further studies on the ecology of the species. While the community ecology of darkling beetles has been studied in several arid regions of the world (STAPP 1997, BLAUM et al. 2009), especially in Israel (KRASNOV & SHENBROT 1996, 1998) and in the Mediterranean (FATTORINI 2006, 2010), little is known about the central Asian region. SAGDY (1996), investigated community pattern of Tenebrionidae in the Ubsunur Hollow Preserve in Tuva, but nothing is known on the ecological communities of the species rich Mongolian fauna

Numerical simulations of neutron star-black hole binaries in the near-equal-mass regime

Simulations of neutron star-black hole (NSBH) binaries generally consider black holes with masses in the range $(5-10)M_\odot$, where we expect to find most stellar mass black holes. The existence of lower mass black holes, however, cannot be theoretically ruled out. Low-mass black holes in binary systems with a neutron star companion could mimic neutron star-neutron (NSNS) binaries, as they power similar gravitational wave (GW) and electromagnetic (EM) signals. To understand the differences and similarities between NSNS mergers and low-mass NSBH mergers, numerical simulations are required. Here, we perform a set of simulations of low-mass NSBH mergers, including systems compatible with GW170817. Our simulations use a composition and temperature dependent equation of state (DD2) and approximate neutrino transport, but no magnetic fields. We find that low-mass NSBH mergers produce remnant disks significantly less massive than previously expected, and consistent with the post-merger outflow mass inferred from GW170817 for moderately asymmetric mass ratio. The dynamical ejecta produced by systems compatible with GW170817 is negligible except if the mass ratio and black hole spin are at the edge of the allowed parameter space. That dynamical ejecta is cold, neutron-rich, and surprisingly slow for ejecta produced during the tidal disruption of a neutron star : $v\sim (0.1-0.15)c$. We also find that the final mass of the remnant black hole is consistent with existing analytical predictions, while the final spin of that black hole is noticeably larger than expected -- up to $\chi_{\rm BH}=0.84$ for our equal mass case

The Effects of Scheduling on Public School Instrumental Music Education in Saint Louis County, Missouri

To determine the effects of scheduling on instrumental music programs in the public school districts of Saint Louis County, Missouri, a questionnaire was distributed to fifty-two instrumental music teachers in twenty-eight districts . We proposed to find common concerns shared by instrumental music teachers with regard to the scheduling of their classes. Our respondents concurred on specific scheduling situations that cause either alteration or complete elimination of their programs. Elementary curriculum is crowded with numerous non-academic offerings which compete for student time. Missouri has recently mandated additional secondary requirements in math and science without raising fine arts credits. This has created a dangerous situation for the fine arts. With the majority of high schools having a six-period day, the rise in academic requirements has put stress on the student wishing to enroll in fine arts courses. Findings indicate a strong need for a seven-period high school day. our results demonstrate a need to educate those responsible for scheduling in the value of the fine arts for a complete and well-rounded education

I\u27ll Go The Route For You

https://digitalcommons.library.umaine.edu/mmb-vp/3199/thumbnail.jp

I\u27m In Love With One Of The Stars

https://digitalcommons.library.umaine.edu/mmb-vp/1790/thumbnail.jp