A5005653713- Noncommutative and Quantum Gravity Theories
- Power Line Communications and Noise
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Neutrino Physics Research
- Quantum Mechanics and Applications
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Relativity and Gravitational Theory
- Advanced Optical Network Technologies
- Wireless Communication Networks Research
- Network Traffic and Congestion Control
- Astrophysics and Cosmic Phenomena
- Energy Efficient Wireless Sensor Networks
- Atomic and Subatomic Physics Research
- Advanced Wireless Communication Techniques
- Wireless Networks and Protocols
- Indoor and Outdoor Localization Technologies
- Quantum Electrodynamics and Casimir Effect
- Underwater Vehicles and Communication Systems
- Advanced MIMO Systems Optimization
- Advanced Differential Geometry Research
- Radiation Detection and Scintillator Technologies
- Cooperative Communication and Network Coding
- Quantum, superfluid, helium dynamics
Technische Universität Dresden
2011-2024
Indiana University Bloomington
2014-2024
Deutsche Telekom (Germany)
2016-2024
Indiana University
2015-2023
Leibniz University Hannover
2016-2023
Devolo (Germany)
2021
Xiamen University
2021
University of Johannesburg
2021
Universidad Nacional Autónoma de México
2007-2011
Aware (United States)
2011
Stability and causality are investigated for quantum field theories incorporating Lorentz $\mathrm{CPT}$ violation. Explicit calculations in the quadratic sector of a general renormalizable Lagrangian massive fermion reveal that no difficulty arises low energies if parameters controlling breaking small, but high either energy positivity or microcausality is violated some observer frame. However, this can be avoided sub-Planck limit nonlocal theory with spontaneous Our analysis supports...
Abstract Neutrinos are one of the most promising messengers for signals new physics Beyond Standard Model (BSM). On theoretical side, their elusive nature, combined with unknown mass mechanism, seems to indicate that neutrino sector is indeed opening a window physics. experimental several long-standing anomalies have been reported in past decades, providing strong motivation thoroughly test standard three-neutrino oscillation paradigm. In this Snowmass21 white paper, we explore potential...
Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology a time-varying fine-structure constant provides an explicit example. Estimates are made for some experimental constraints.
Within the classical Maxwell-Chern-Simons limit of standard-model extension, emission light by uniformly moving charges is studied confirming possibility a \ifmmode \check{C}\else \v{C}\fi{}erenkov-type effect. In this context, exact radiation rate for charged magnetic point dipoles determined and found in agreement with phase-space estimate under certain assumptions.
We propose a correspondence between the description of emergent Lorentz symmetry in condensed-matter systems and established general effective field theory for violation fundamental theories spacetime matter. This has potential implications both directions. illustrate proposal by investigating its consequences spectral transport properties Dirac Weyl semimetals. Particular realizations this framework give rise to nodal spectra with lines rings. demonstrate bulk-boundary bulk topological...
The emission of electromagnetic radiation by charges moving uniformly in a Lorentz-violating vacuum is studied. analysis performed within the classical Maxwell-Chern-Simons limit Standard-Model Extension and confirms possibility \ifmmode \check{C}\else \v{C}\fi{}erenkov-type effect. In this context, various properties \v{C}\fi{}erenkov including rate, polarization, propagation features, are discussed, backreaction on charge investigated. An interpretation effect supplementing conventional...
In the context of threshold investigations Lorentz violation, we discuss fundamental principle coordinate independence, role an effective dynamical framework, and conditions positivity causality. Our analysis excludes a variety previously considered Lorentz-breaking parameters opens avenue for viable dispersion-relation violation.
We consider the possibility that Lorentz violation can generate differences between limiting velocities of light and charged matter. Such effects would lead to efficient vacuum Cherenkov radiation or rapid photon decay. The absence such for 104.5 GeV electrons at Large Electron Positron collider 300 photons Tevatron therefore constrains this type breakdown. Within context standard-model extension, these ideas imply an experimental bound level...
All quadratic translation- and gauge-invariant photon operators for Lorentz breakdown are included into the Stueckelberg Lagrangian massive photons in a generalized \xi-gauge. The corresponding dispersion relation tree-level propagator determined exactly, some leading-order results derived. question of how to include such Lorentz-violating effects perturbative quantum-field expansion is addressed. Applications these within Lorentz-breaking quantum field theories regularization infrared...
In some quantum theories of gravity, deviations from the laws relativity could be comparatively large while escaping detection to date. neutrino sector, precision experiments with beta decay yield new and improved constraints on these countershaded violations. Existing data are used extract bounds $3 \times 10^{-8}$ GeV magnitudes two four possible coefficients, estimates provided future attainable sensitivities in a variety experiments.
The classical propagation of certain Lorentz-violating fermions is known to be governed by geodesics a four-dimensional pseudo-Finsler $b$ space parametrized prescribed background covector field. This work identifies systems in physics that are the three-dimensional version Finsler and constructs geodesic for sample non-constant choice covector. existence these analogues demonstrates spaces possess applications conventional physics, which may yield insight into SME on curved manifolds.
The modified Dirac equation in the Lorentz-violating Standard-Model Extension (SME) is considered. Within this framework, construction of a hermitian Hamiltonian to all orders Lorentz-breaking parameters investigated, discrete symmetries and first-order roots dispersion relation are determined, various properties eigenspinors discussed.
Many candidate fundamental theories contain scalar fields that can acquire spacetime-varying expectation values in a cosmological context. Such scalars typically obey Lorentz-violating effective dispersion relations. We illustrate this fact within simple supergravity model also exhibits the observed late-time acceleration and implies varying electromagnetic couplings.
Asymptotic single-particle states in quantum field theories with small departures from Lorentz symmetry are investigated perturbatively focus on potential phenomenological ramifications. To this end, one-loop radiative corrections for a sample Lorentz-violating Lagrangian contained the Standard-Model Extension studied at linear order breakdown. It is found that spinor kinetic operator, and thus free-particle physics, modified by operators absent original Lagrangian. As consequence of result,...
We report the first experimental upper bound to our knowledge on possible in-matter torsion interactions of neutron from a recent search for parity violation in spin rotation liquid He-4. Our experiment constrains coefficient $ζ$ consisting linear combination parameters involving time components fields $T^μ$ and $A^μ$ nucleons electrons helium which violates parity. an $|ζ|<9.1x10^{-23}$ GeV at 68% confidence level indicate other physical processes that could be analyzed constrain torsion.
The absence of vacuum Cherenkov radiation for 104.5 GeV electrons and positrons at the LEP collider CERN combined with observed stability 300 photons Tevatron constrains deviations speed light relative to maximal attainable electrons. Within standard-model extension, limit -5.8x10(-12)<or=kappatr-4/3ce00<or=1.2x10(-11) is extracted, which sharpens previous bounds by more than 3 orders magnitude. potential further refinements this terrestrial experiments astrophysical observations discussed.
The possibility of anisotropies in the speed light relative to limiting electrons is considered. absence sidereal variations energy Compton-edge photons at European Synchrotron Radiation Facility's GRAAL facility constrains such representing first nonthreshold collision-kinematics study Lorentz violation. When interpreted within minimal standard-model extension, this result yields two-sided limit 1.6×10−14 95% confidence level on a combination parity-violating photon and electron...
One of the most fundamental symmetries in physics is CPT invariance. This article reviews conditions under which symmetry holds by recalling two proofs theorem: The original Lagrangian-based analysis and more rigorous one context axiomatic quantum field theory. presentation followed a discussion major physical implications that arise from symmetry. Motivated recent theoretical experimental interest tests, various approaches to violation are mentioned, it briefly discussed how they evade...
Recently, there is an increasing popularity of video streaming services over IP networks, e.g., IPTV, whose successes strongly depend on the quality experienced by end users. However, QoE/QoSE (Quality Experience/Quality Service Experienced) these can be degraded due to packet losses during delivery. On other side, understand how loss impacts essentially for ISPs optimize their network design and engineering. In this paper we present our experimental results evaluating MPEG-4 in presence...
A localization algorithm that is often used by sensor nodes Min-Max [1] [2]. This can be easily executed due to the fact it principally consists of few additions, subtractions and logical comparisons. However, provides a coarse position estimation. In our proposal we improve accuracy including simple extra operations. We compare extended (E-Min-Max) with other algorithms using simulation.
We consider the neutrino (and antineutrino) flavors arriving at Earth for neutrinos produced in annihilation of weakly interacting massive particles (WIMPs) sun's core. Solar-matter effects on flavor propagation resulting $\ensuremath{\gtrsim}\mathrm{GeV}$ are studied analytically within a density-matrix formalism. Matter effects, including mass-state level crossings, influence fluxes considerably. The exposition herein is somewhat pedagogical, that it starts with adiabatic evolution single...