Article
Physics, Multidisciplinary
Brett Altschul
Summary: Experimental tests of Lorentz violation are crucial for our understanding of fundamental physics and have sparked significant interest in the 21st century. High-energy astrophysical observations and laboratory tests using optical atomic clocks provide competing bounds for natural forms of Lorentz violation involving electrons and positrons. The advantages and limitations of both approaches are discussed, along with potential future developments.
Article
Physics, Particles & Fields
Sapan Karki, Brett Altschul
Summary: This article investigates redundancies of description in effective quantum field theories that allow for the possibility of Lorentz symmetry violation. The study shows that different renormalization schemes may lead to different expressions for the renormalization group beta-functions, but the renormalization group scaling of physically observable quantities appears not to be affected by this scheme dependence.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
Celio A. Moura, Lucas Quintino, Fernando Rossi-Torres
Summary: We analyze the expected arrival time spectrum of supernova neutrinos and compute the expected number of events in future detectors. We develop a method to compute the sensitivity to any variable affecting neutrino time of flight. We apply this method to study neutrino mass values and Lorentz invariance violation.
Article
Astronomy & Astrophysics
Chengyi Li, Bo-Qiang Ma
Summary: We present a scenario based on the space-time foam model from string/D-brane theory in which neutrinos can have linearly energy dependent speed variation and an asymmetry between neutrinos and antineutrinos, suggesting a potential violation of Lorentz and CPT symmetry for neutrinos. This scenario is supported by a phenomenological conjecture linking IceCube ultrahigh-energy neutrino events with gamma-ray bursts and is consistent with constraints imposed by energy-losing decay channels on superluminal neutrino velocities. We argue that violations of energy-momentum conservation during decay could explain the stable propagation of these neutrinos and the evasion of relevant constraints.
Review
Astronomy & Astrophysics
Rodrigo Guedes Lang, Humberto Martinez-Huerta, Vitor de Souza
Summary: Compelling evidence for Lorentz invariance violation would require a major revision of modern physics. This paper reviews the potential of ultra-high-energy astroparticles in setting limits on Lorentz invariance violation, discusses the standard framework of Lorentz invariance violation studies in astroparticle physics, and addresses the current status of Lorentz invariance violation tests using experimental data on ultra-high-energy photons and cosmic rays.
Article
Physics, Multidisciplinary
Simran Arora, Pradyumn Kumar Sahoo
Summary: The possibility of crossing the phantom divide line in the extension of symmetric teleparallel gravity or f(Q) gravity is investigated in this study. The cosmic evolution of the effective equation of state parameter for dark energy is studied using exponential, logarithmic, and combined f(Q) theories. It is demonstrated that future crossings of the phantom dividing line are a generic feature of feasible f(Q) gravity models.
ANNALEN DER PHYSIK
(2022)
Article
Multidisciplinary Sciences
Vladimir Cheslavovich Zhukovsky
Summary: This paper explores the influence of various external forces on the radiation effect of charged particles, focusing on the example of an electron in a magnetic field. The study considers the anomalous magnetic moment and possible violation of Lorentz invariance, and calculates the synchrotron radiation characteristics. The presence of an electromagnetic wave and the inhomogeneity of the magnetic field are also taken into account in the calculation of stimulated synchrotron radiation. The paper also proposes a method to calculate synchrotron radiation in real circumstances without approximating the radiative amplitudes themselves.
Article
Astronomy & Astrophysics
N. Dimakis, Andronikos Paliathanasis
Summary: In this study, a chiral cosmological model with two scalar fields minimally coupled to gravity was considered, leading to a general solution of the field equations in a FLRW spacetime with massless fields and a cosmological constant. The symmetrical minisuperspace configuration resulted in scenarios corresponding to quintessence, quintom, or phantom cases, depending on the parameters. The canonical quantization of the model distinguished between different families of quantum states, and the crossing of the phantom line was related to the existence of free or bound states for the Casimir operator of the fields' symmetry algebra. The classical singularity present in the quintessence solution was also resolved at the quantum level.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Astronomy & Astrophysics
D. J. Bartlett, H. Desmond, P. G. Ferreira, J. Jasche
Summary: Constraints on the photon mass m(gamma) and the QG length scale l(QG) were derived using spectral lag data, with the results indicating tight constraints at a 95% confidence level. The constraints are robust to the choice of noise model, and the QG constraint is among the tightest in current studies.
Article
Astronomy & Astrophysics
Spyros Konitopoulos, Emmanuel N. Saridakis, P. C. Stavrinos, A. Triantafyllopoulos
Summary: This work explores the foundations of generalized scalar-tensor theories derived from vector bundle constructions, defining a space with two scalar fields over a pseudo-Riemannian base manifold. The novel geometrical structure leads to modified Friedmann equations in a cosmological context, introducing extra terms and enabling the appearance of an effective dark energy sector.
Article
Astronomy & Astrophysics
Jie Zhu, Bo-Qiang Ma
Summary: Previous studies have shown that high-energy photons appear earlier than low-energy photons at the source of GRBs, but in the scenario of energy-dependent light speed variation, high-energy photons travel slower than low-energy photons and are typically detected later. Recent research analyzing high-energy photon events observed earlier than low-energy photons from FGST supports the pre-burst scenario of high-energy photons from GRBs and the energy dependence of light speed.
Article
Physics, Multidisciplinary
Xia Tan, Jie Zhang, Ran Li, Shu-Zheng Yang
Summary: In this study, a new form of the fermions dynamic equation under the background of the arbitrarily accelerating black hole, which contains Lorentz invariance violation, is investigated. The quantum tunneling radiation of the arbitrarily accelerating black hole is correctly modified, and the corrected physical quantities such as black hole temperature and quantum tunneling rate are thoroughly discussed.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2023)
Article
Physics, Particles & Fields
Sourav Sur, Ashim Dutta, Hiyang Ramo Clothe
Summary: The theory extends the basic formalism of mimetic-metric-torsion gravity theory, showing geometrically how the mimetic scalar field acts as the source of both the trace and axial modes of torsion. It maintains conformal symmetry and spatial parity symmetry, demonstrating a geometric unification of the cosmological dark sector and the feasibility of a super-accelerating regime during the universe's evolution. The theory also predicts a smooth crossing of the phantom barrier at low red-shift and determines the extent of super-acceleration by examining the evolution of relevant torsion parameters.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Multidisciplinary
M. Koussour
Summary: In this study, we investigate the history of the cosmos using an extension of symmetric teleparallel gravity called Weyl-type f(Q,T) gravity. We derive the Hubble parameter from a proposed deceleration parameter and apply it to the Friedmann equations. The best fit values of the model parameters support a crossing of the phantom divide line, suggesting that Weyl-type f(Q,T) gravity can provide an alternative to dark energy in explaining cosmic acceleration.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Astronomy & Astrophysics
Chengyi Li, Bo-Qiang Ma
Summary: The Large High Altitude Air Shower Observatory (LHAASO) recently reported the detection of gamma-ray emissions with energies up to 1.1 PeV from the Crab Nebula. By studying the absence of vacuum Cherenkov effect, the researchers have improved the constraints on linear-order Lorentz invariance violation in the dispersion relations of electrons. The results show that the Lorentz invariance violation on electrons is severely constrained and compatible with certain models of quantum gravity.
Article
Physics, Multidisciplinary
Fateme Rajabi, Kourosh Nozari
CANADIAN JOURNAL OF PHYSICS
(2019)
Article
Physics, Mathematical
Kourosh Nozari, Naser Sadeghnezhad
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2019)
Article
Physics, Particles & Fields
M. Roushan, K. Nozari
EUROPEAN PHYSICAL JOURNAL C
(2019)
Article
Astronomy & Astrophysics
S. Davood Sadatian, Alireza Sepehri
MODERN PHYSICS LETTERS A
(2019)
Article
Astronomy & Astrophysics
K. Nozari, P. Dehghani
Article
Physics, Mathematical
S. Saghafi, K. Nozari, A. D. Kamali
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2019)
Article
Astronomy & Astrophysics
R. Shojaee, K. Nozari, F. Darabi
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2020)
Article
Physics, Particles & Fields
M. Roushan, K. Nozari
EUROPEAN PHYSICAL JOURNAL C
(2020)
Article
Astronomy & Astrophysics
R. Shojaee, K. Nozari, F. Darabi
Summary: In this study, we investigated cosmological inflation in a Galileon inflationary model with the E-model potential to identify possible alpha-attractors. By analyzing the evolution of perturbations and considering the reheating phase post-inflation, we found universal values for the scalar spectral index and tensor-to-scalar ratio. Comparing our results with Planck data, we discovered constraints on the model's parameter space, including the potential for a longer reheating phase and observational viable values of ns associated with a larger temperature range.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2021)
Article
Engineering, Aerospace
S. Davood Sadatian, M. Gharjeh Ghiyaei
Summary: By introducing the Kappa distribution function and considering dimensionless variables, the Bohm sheath equation in a plasma is derived. The study investigates the effects of spectral index and potential degrees of freedom on solitons with positive and negative potentials in different regions through numerical analysis.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Operations Research & Management Science
S. Abbas Sadatian, S. Davood Sadatian, Masoumeh Asiaei, S. Ali Reza Davoodi
Summary: Limited resources drive companies to utilize technological tools to increase productivity and efficiency. Supplier selection significantly affects corporate performance, and this study prioritizes practical criteria for supplier selection in an Electricity Distribution Company using the Analytical Hierarchy Process and Goal Programming. The results indicate the potential of achieving better solutions using an interactive model.
Article
Physics, Mathematical
S. Davood Sadatian, A. Sabouri
Summary: The study introduces a new model of agegraphic dark energy based on three generalized uncertainty principles, investigating the universe's evolution in different eras and describing the evolution and expansion of the universe in each subsection.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2022)
Article
Physics, Mathematical
S. Davood Sadatian, A. Saburi
Summary: In this paper, the thermodynamics of a dark energy bulk viscosity model as a cosmic fluid is investigated. The thermodynamics of cosmic fluids in the dark energy bulk viscosity model and the general relationships are studied, followed by an analysis of the thermodynamic relationships of Eckart's theory. The relations between the pressure, energy density, and bulk viscosity coefficient of the cosmic fluid are obtained for different states.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2023)
Article
Astronomy & Astrophysics
Kourosh Nozari, Narges Rashidi
ASTROPHYSICAL JOURNAL
(2019)
Article
Physics, Multidisciplinary
S. Davood Sadatian
