Search results for "conservation."
showing 10 items of 1994 documents
Axionic and nonaxionic electrodynamics in plane and circular geometry
2023
Various aspects of axion electrodynamics in the presence of a homogeneous and isotropic dielectric medium are discussed. 1. We consider first the "antenna-like" property of a planar dielectric surface in axion electrodynamics, elaborating on the treatment given earlier on this topic by Millar {\it et al.} (2017). We calculate the electromagnetic energy transmission coefficient for a dielectric plate, and compare with the conventional expression in ordinary electrodynamics. 2. We consider the situation where the medium exterior to the plate, assumed elastic, is "bent back" and glued together, so that we obtain a circular dielectric string in which the waves can propagate clockwise or counter…
Implications for dark matter direct detection in the presence of LIGO-motivated primordial black holes
2019
We discuss formation of dark matter (DM) mini-halos around primordial black holes (PBHs) and its implication on DM direct detection experiments, including axion searches. Motivated by LIGO observations, we consider $f_{\textrm{DM}} \simeq 0.01$ as the fraction of DM in PBHs with masses $10 M_{\odot} - 70 M_{\odot}$. In this case, we expect the presence of dressed PBHs after Milky Way halo formation with mini-halo masses peaked around $M_{\textrm{halo}} \sim (50-55) M_{\textrm{PBH}}$. We analyze the effect of tidal forces acting on dressed PBHs within the Milky Way galaxy. In the solar neighborhood, the mini-halos are resistant against tidal disruption from the mean-field potential of the ga…
Electromagnetic Duality Anomaly in Curved Spacetimes
2016
The source-free Maxwell action is invariant under electric-magnetic duality rotations in arbitrary spacetimes. This leads to a conserved classical Noether charge. We show that this conservation law is broken at the quantum level in presence of a background classical gravitational field with a non-trivial Chern-Pontryagin invariant, in a parallel way to the chiral anomaly for massless Dirac fermions. Among the physical consequences, the net polarization of the quantum electromagnetic field is not conserved.
Normalization of Killing vectors and energy conservation in two-dimensional gravity
1999
We explicitly show that, in the context of a recently proposed 2D dilaton gravity theory, energy conservation requires the ``natural'' Killing vector to have, asymptotically, an unusual normalization. The Hawking temperature $T_H$ is then calculated according to this prescription.
Abelian current algebra and the Virasoro algebra on the lattice
1993
We describe how a natural lattice analogue of the abelian current algebra combined with free discrete time dynamics gives rise to the lattice Virasoro algebra and corresponding hierarchy of conservation laws.
Multiple approaches to identify bacteria in archaeological waterlogged wood
2013
This study was carried out in collaboration with Soprintendenza del Mare (SM) that started, since 2004, to plan and realize underwater archaeological parks, such as in the Sicilian islands of Pantelleria (Gadir), Levanzo (Cala Minnola), Ustica (Falconiera), Panarea (Basiluzzo) and Filicudi (Capo Graziano). In situ conservation, as well as virtual exhibitions of the same topics, can contribute to ensure the protection and best fruition of underwater cultural heritage. The focus of this study was the identification of bacterial colonies in waterlogged wood samples from the rostrum of a excellent workmanship, that is very likely one of the wrecks attributed to Sextus Pompey fleet (36 BC) and d…
Landscape 100: How Finland, Estonia and Latvia Used Landscape in Celebrating their Centenary Anniversaries
2019
Abstract In the aftermath of what was then the Great War several European countries like Finland, Estonia and Latvia gained independence, marking their centenary jubilees 2017–2018. This paper observes how landscapes were used in anniversary celebrations and what historical themes were foregrounded and which omitted, revealing how collective historical commemoration in landscape enacts within national identity framework depending also on how landscape is understood in each respective country.
Le monastère Saint-Pierre d’Osor (île de Cres) : neuvième campagne d’études archéologiques
2015
During the 2014 campaign exhaustive excavations of the early medieval mausoleum and monastic tombs situated between the mausoleum and the bell tower south of the abbey church of St Peter in Osor were completed. The results of the excavation of the interior of the reduced church revealed several floor levels that are contemporary to the Romanesque basilica, as well as the foundations of the Romanesque chancel screen situated in front of the north apse, and the presence of many burials. Some of them can be identified as privileged tombs, due to their position and their contents. Several floor levels corresponding to the phases anterior to the Romanesque church were also discovered, although i…
Recent results from Borexino
2016
Journal of Physics Conference Series. - 798, International Conference on Particle Physics and Astrophysics : 10-14 October 2016, Moscow, Russian Federation / proceedings editors: 1. issue: cosmic rays: Arkady Galper (MEPhI, Moscow, Russia) [und 7 andere] 2nd International Conference on Particle Physics and Astrophysics, ICPPA 2016, Moscow, Russia, 11 Oct 2016 - 14 Oct 2016; Bristol : IOP Publ., Journal of Physics Conference Series, 798, 012114 pp. (2017). doi:10.1088/1742-6596/798/1/012114
Interpreting protohistoric societies through place names of landscape features: a case study in València, Spain
2021
Protohistoric place names, created before written history and related to extinct languages, are analysed in this article. Our case study deals with place names of current towns (over 20,000 inhabit...