102,665 research outputs found
Spin Rotation Coupling in muon g-2 Experiments
No full textSpin-rotation coupling, or Mashhoon effect, is a phenomenon associated with rotating observers. We show that the effect plays a fundamental role in the determination of the anomalous magnetic moment of the muon, is sizable and violates the principle of equivalence
Matter-antimatter asymmetry induced by Barbero-Immirzi parameter
No full textWe review the baryon asymmetry generated in the early Universe in the framework of the metric-spinor gravity with the Holst term, which accounts for the Barbero-Immirzi parameter. For the generation of the matter-antimatter asymmetry, we have considered the model in which the time derivative of the Ricci scalar couples with matter currents (this model is known in the literature as gravitational baryogenesis). By using the current bounds on the parameter of the asymmetry, the ratio of baryon number to the entropy density, we infer a bound on the parameters characterizing the model under consideration (that is, the cosmological model in the presence of the torsion and Barbero-Immirzi parameter).(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). Funded by SCOAP3
Dark matter in modified cosmologies
No full textThe IceCube experiment discovered a high-energy astrophysical neutrino flux with energies of the order of PeV. To explain this phenomenon one may consider the minimal 4-dimensional operator. An interesting possibility is to also explain the relic abundance of DM in the Universe. Assuming that the cosmological background evolves according to the standard cosmological model, this model fails since the rate of DM decay needed to get the correct DM relic abundance differs by many orders of magnitude with respect that one needed to explain the IceCube data. We show that such a discrepancy can be solved if the Universe evolution is governed by a modified cosmology
Searching for dark matter axions with Berry phase
No full textWe discuss novel aspects of the interaction of axions-like particles (ALP) with superfluids, superconductors in particular, and determine an induced Berry phase that is topologically singular and contributes to the generation of string-like structures. The latter are similar to vortices in superfluids. We suggest that measuring the currents generated by the Berry phase of ALP axions would enable the study of low mass regions of the ALP spectrum otherwise unobservable
Gamma Ray Bursts in Brans-Dicke Theory
No full textGamma-Ray Bursts (GRBs) production is discussed in the framework of the Brans-Dicke (BD) theory of gravity. We derive the effective potential and the acceleration of a scalar particle propagating in a gravitational field described by BD theory. The rate of the energy radiated by charged particles is also calculated. Constraints on parameters entering the BD theory are fixed in order to reproduce the typical outputs energy of GRBs
Neutrino Oscillations in Exotic Geometries and the Equivalence Principle Violation
No full textTaking into account the violation of the equivalence principle, we analyze the propagation of neutrinos in the gravitational field generated by wormholes. The analysis is performed for massive and massless neutrinos. By using the constraints on the (negative) mass of wormholes, which is of the order of stellar-substellar masses, we determine constraints on Δf which characterizes the degree of violation of the equivalence principle
Treatment of Electrical Storm with Amiodarone in Brugada Syndrome- an Unexpected Protective Effect
No full textWe are reporting on a 53 year old man with proven Brugada syndrome and ICD implantation for resuscitation in context of polymorphic VT. After recurrent arrhythmia he was treated with Amiodarone. This showed to have a protective effect despite various reports suggesting avoiding Amiodarone in Brugada syndrome
On the consistency of DSR models for multiparticle systems
No full textThe aim of the thesis is to provide a new original solution proposal to the infamous soccer-ball problem in the k-Poincaré inspired DSR (Doubly or Deformed Special Relativity) theory. More specifically, through the analysis of the kinematical properties of a composite system, we show that the single-particle deformation effects typical of the k-Poincaré setup should become weaker and weaker as the number of particles composing the system grows higher. After proposing a consistent definition of the "total" symmetry algebra of this system, we explore the so-called k-galilean limit of the theory. In particular, by avoiding the special relativistic no-interaction theorem, we are able to perform a first analysis of the quantum mechanical properties of an interacting two-particle system in the non-commutative k-Poincaré framework
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