Article
Physics, Multidisciplinary
Chen Zhang, Z. Y. Chen, Zheng Zhang, Y. X. Zhao
Summary: In this work, a novel theory is developed to study momentum-space nonsymmorphic space groups (k-NSGs) using projective representations of space groups. The theory can identify the corresponding real-space symmorphic space groups (r-SSGs) and construct the projective representation that leads to the k-NSG. The broad applicability of the theory is demonstrated by showing that all k-NSGs can be realized by gauge fluxes over real-space lattices.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Yue Zhang, Yu-Xuan Luo, Quan Liu, Jian-You Guo
Summary: In this study, the Pseudospin symmetry (PSS) in resonant states in deformed nuclei is examined for the first time by solving the Dirac equation in the complex-momentum representation using a potential with quadrupole deformation obtained from relativistic mean-field calculations. By analyzing the energies, widths, and density distributions of single-particle resonant states, it is found that the PSS of resonant states is well preserved in deformed nuclei, with small pseudospin splittings and similar radial density distributions between the resonant pseudospin doublets compared to bound states. Furthermore, the dependencies of PSS on nuclear deformations and potential shape are comprehensively studied, providing insights into the evolution of resonant pseudospin doublets in weakly-bound deformed nuclei and their exotic properties.
Article
Materials Science, Multidisciplinary
Matthew M. Roberts, Toby Wiseman
Summary: In this study, we investigate the Dirac equation of graphene using a real space gradient expansion and find a previous research error. Generic spatially varying hopping functions lead to large magnetic fields, while fine-tuning the magnetic field to be small allows for a consistent truncation.
Article
Physics, Particles & Fields
Christian Pfeifer, Jose Javier Relancio
Summary: This article presents a systematic analysis of how deformed relativistic kinematics can be lifted to curved spacetimes in terms of a self-consistent cotangent bundle geometry. The analysis shows that momentum space metrics can be consistently lifted to curved spacetimes if they satisfy certain conditions. The article also discusses the connection between this construction and non-commutative spacetimes.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
J. Bonnard, J. Dobaczewski, G. Danneaux, M. Kortelainen
Summary: Within the nuclear DFT approach, the magnetic dipole and electric quadrupole moments for paired nuclear states were determined. Calculations were performed for all deformed open-shell odd nuclei and good agreement with experimental data was obtained. It was shown that the intrinsic magnetic dipole moments do not represent viable approximations of the spectroscopic ones.
Article
Astronomy & Astrophysics
P. I. C. Caneda, G. Menezes
Summary: The study extends reduced quantum electrodynamics to curved spaces and investigates the one-loop optical conductivity of graphene, showing a zero one-loop beta function and the emergence of a curvature-induced effective chemical potential contribution.
Article
Astronomy & Astrophysics
Vladimir Toussaint, Jorma Louko
Summary: The study examines the effects of quantized massive scalar fields in spatially compact cosmological spacetimes, showing that the freedom in respective in and out states is determined by two real parameters in the presence of a massive zero mode. Analyzing both untwisted and twisted scalar fields in specific spacetime, it is demonstrated that the choice of massive in zero mode state significantly impacts the response of an inertial Unruh-DeWitt detector, particularly in the excitation part of the spectrum. Special considerations are given to the detector's peculiar velocity with respect to comoving cosmological observers, with the strongest effect observed in the in vacuum of the untwisted field.
Article
Physics, Particles & Fields
Fabian Wagner
Summary: The minimal and maximal uncertainties of position measurements are considered to be important characteristics of low-energy quantum and classical gravity. This study shows that the Generalized Extended Uncertainty Principle can be described in terms of quantum dynamics on a general curved cotangent manifold, with the curvature tensors being related to the noncommutativity of coordinates and momenta. The covariance of the approach leads to interesting subclasses of noncommutative geometries and enables the derivation of anisotropically deformed uncertainty relations from general background geometries.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Particles & Fields
Claudio Coriano, Stefano Lionetti, Matteo Maria Maglio
Summary: This study analyzes the effects of parity-odd trace anomalies on parity-odd correlators. It finds that in certain cases, these correlators can be non-zero, and the presence of parity-odd trace anomalies leads to non-zero values for certain correlators.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Hassan Firouzjahi
Summary: This article revisits the quantum cosmological constant problem and emphasizes the important role of the de Sitter horizon's zero-point energy. The study argues that fields with a de Sitter horizon of zero-point energy comparable to the Friedmann-Lemattre-Robertson-Walker Hubble radius are the main contributors to dark energy. However, the zero-point energy of heavy fields develops nonlinearities on sub-Hubble scales and cannot contribute to dark energy. The proposal speculates that the field of the lightest neutrino, having a mass comparable to the present background photon temperature, may provide a resolution for both the old and new cosmological constant problems. The proposal predicts multiple transient periods of dark energy in the early and late expansion history of the Universe, which can resolve the H-0 tension problem.
Article
Materials Science, Multidisciplinary
M. Selch, M. Suleymanov, M. A. Zubkov, C. X. Zhang
Summary: The Hall conductivity for the intrinsic anomalous quantum Hall effect in homogeneous systems is determined by a topological invariant composed of the Green function dependent on the momentum of the quasiparticle. In the presence of an external magnetic field, the expression for Hall conductivity remains valid if certain representations of the Green function are used. These representations involve infinite-dimensional matrices or the Moyal products, but they are more complicated and potentially impractical for calculations.
Article
Physics, Multidisciplinary
Susobhan Mandal, Subhashish Banerjee
Summary: This paper presents a local construction of the S-matrix in quantum field theory in curved spacetime using Riemann-normal coordinates, overcoming the challenge of a global description of the S-matrix in arbitrary curved spacetime. Scattering amplitudes and cross sections of some scattering processes are computed in a generic curved spacetime, demonstrating that local observables can probe features of curved spacetime. The compatibility of the local construction of the S-matrix with spacetime symmetries is also discussed in detail.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Astronomy & Astrophysics
H. Firouzjahi, Mohammad Ali Gorji, Shinji Mukohyama, Alireza Talebian
Summary: In multiple field inflationary scenarios, the accumulated energy density of excited entropy modes can serve as dark matter. In a negatively curved field space, subhorizon entropy modes can be excited through tachyonic instability induced by the negative curvature, leading to a new dark matter scenario with mass larger than the Hubble expansion rate. The spectral density in this model has a peak at a smaller scale compared to models based on flat field space, making it observationally distinguishable.
Article
Physics, Multidisciplinary
Ozlem Yesiltas, Ikram Imane Kouachi
Summary: In this paper, the Dirac equation in the presence of PT / non-PT-symmetric potential interactions on a two dimensional gravitational static background with position-dependent mass has been studied. The exponential metric component allows the reduction of the Dirac operator to a general supersymmetric model with mass changing along coordinates. By using Lie algebras and supersymmetric quantum mechanical approaches, the eigenvalues of the Dirac operator for complex Morse and trigonometric complex Scarf-II potentials SL(2, C) are obtained. Additionally, a general Sturm-Liouville type equation is derived through a convenient mapping, which enables the study of the system within ?-pseudo-Hermiticity. The ? operator is determined for the examples of complex trigonometric Rosen-Morse potential and complex Morse potentials with real and complex parameters, and the solutions are obtained with energy values and probability densities.
Article
Physics, Particles & Fields
Maxim Grigoriev, Adiel Meyer, Ivo Sachs
Summary: We study gauge theories of background fields associated to BRST quantized spinning particle models and identify background-independent algebraic structures which allow to systematically reduce the spectrum of fields and subject some of them to dynamical equations of motion. More specifically, we construct a manifestly background-independent extension of the model based on N = 2 spinning particle. The resulting system describes an on-shell spin-1 field coupled to off-shell background fields including metric and dilaton. Tensoring with a given Lie algebra results in a non-abelian extension of the model.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
