scholarly journals Constraints on global symmetry breaking in quantum gravity from cosmic birefringence measurements

2021 ◽  
pp. 136752
Author(s):  
James Alvey ◽  
Miguel Escudero Abenza
Keyword(s):  
Quantum Gravity ◽  
Symmetry Breaking ◽  
Global Symmetry

scholarly journals Global symmetry, Euclidean gravity, and the black hole information problem

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Daniel Harlow ◽  
Edgar Shaghoulian
Keyword(s):  
Black Hole ◽  
Quantum Gravity ◽  
Global Symmetries ◽  
Close Connection ◽  
Usual Sense ◽  
Global Symmetry ◽  
Recent Argument ◽  
Black Hole Information ◽  
Information Problem ◽  
Low Dimensional

Abstract In this paper we argue for a close connection between the non-existence of global symmetries in quantum gravity and a unitary resolution of the black hole information problem. In particular we show how the essential ingredients of recent calculations of the Page curve of an evaporating black hole can be used to generalize a recent argument against global symmetries beyond the AdS/CFT correspondence to more realistic theories of quantum gravity. We also give several low-dimensional examples of quantum gravity theories which do not have a unitary resolution of the black hole information problem in the usual sense, and which therefore can and do have global symmetries. Motivated by this discussion, we conjecture that in a certain sense Euclidean quantum gravity is equivalent to holography.

Global-symmetry breaking of turbulent puffs in rectangular duct flow

2020 ◽  
Vol 2020 (0) ◽  
pp. OS02-04
Author(s):  
Akito KUNIHIRO ◽  
Masaki SHIMIZU ◽  
Genta KAWAHARA
Keyword(s):  
Symmetry Breaking ◽  
Global Symmetry ◽  
Duct Flow ◽  
Rectangular Duct

scholarly journals Kaonic Atoms to Investigate Global Symmetry Breaking

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 547 ◽  
Author(s):  
Catalina Curceanu ◽  
Carlo Guaraldo ◽  
Diana Sirghi ◽  
Aidin Amirkhani ◽  
Ata Baniahmad ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Precise Measurement ◽  
Relative Energy ◽  
Kaonic Hydrogen ◽  
Global Symmetry ◽  
Nucleus Interaction ◽  
Kaonic Atoms ◽  
Kaonic Deuterium ◽  
Energy Quantum ◽  
Scattering Lengths

Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon ( K ¯ N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DA Φ NE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021.

scholarly journals Stable Spatially Localized Configurations in a Simple Structure—A Global Symmetry-Breaking Approach

2020 ◽  
Vol 142 (1) ◽  
pp. 163-199
Author(s):  
Shrinidhi S. Pandurangi ◽  
Ryan S. Elliott ◽  
Timothy J. Healey ◽  
Nicolas Triantafyllidis
Keyword(s):  
Symmetry Breaking ◽  
Simple Structure ◽  
Global Symmetry

Quantum chromodynamics

2018 ◽  
Author(s):  
Marcos Marino
Keyword(s):  
Symmetry Breaking ◽  
Dirac Operator ◽  
Global Symmetries ◽  
Quantum Chromodynamics ◽  
Random Matrix Theory ◽  
Random Matrix ◽  
Degrees Of Freedom ◽  
Chemical Potential ◽  
Matrix Theory ◽  
Global Symmetry

This article focuses on chiral random matrix theories with the global symmetries of quantum chromodynamics (QCD). In particular, it explains how random matrix theory (RMT) can be applied to the spectra of the Dirac operator both at zero chemical potential, when the Dirac operator is Hermitian, and at non-zero chemical potential, when the Dirac operator is non-Hermitian. Before discussing the spectra of these Dirac operators at non-zero chemical potential, the article considers spontaneous symmetry breaking in RMT and the QCD partition function. It then examines the global symmetries of QCD, taking into account the Dirac operator for a finite chiral basis, as well as the global symmetry breaking pattern and the Goldstone manifold in chiral random matrix theory (chRMT). It also describes the generating function for the Dirac spectrum and applications of chRMT to QCD to gauge degrees of freedom.

scholarly journals SCHWINGER–DYSON EQUATIONS IN 2-D INDUCED GRAVITY IN COVARIANT GAUGES

1994 ◽  
Vol 09 (29) ◽  
pp. 2681-2689 ◽  
Author(s):  
E. ELIZALDE ◽  
S. D. ODINTSOV ◽  
YU. I. SHIL'NOV
Keyword(s):  
Numerical Analysis ◽  
Quantum Gravity ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Chiral Symmetry ◽  
Chiral Symmetry Breaking ◽  
Ladder Approximation ◽  
Coupling Constant ◽  
Induced Gravity ◽  
Negative Cosmological Constant

We formulate the Schwinger–Dyson equations in the ladder approximation for 2-D induced quantum gravity with fermions using covariant gauges of harmonic type. It is shown that these equations can be formulated consistently in a gauge of Landau type (for negative cosmological constant). A numerical analysis of the equations hints towards the possibility of chiral symmetry breaking, depending on the value of the coupling constant.

SYMMETRY BREAKING AND ORDER PARAMETERS OF THE HUBBARD MODEL

1992 ◽  
Vol 06 (03) ◽  
pp. 151-159 ◽  
Author(s):  
ROBERTO LIVI ◽  
ARIANNA MONTORSI ◽  
MARIO RASETTI
Keyword(s):  
Symmetry Breaking ◽  
Hubbard Model ◽  
Order Parameter ◽  
Order Parameters ◽  
Global Symmetry ◽  
Linearization Technique ◽  
Disordered Phase ◽  
Complete Symmetry

The effects of different linearization procedures as breaking of the global symmetry of the Hubbard model recently discovered by Yang and Zhang are discussed, together with the ensuing order parameters. In particular it is pointed out how only the Fermi linearization technique allows us both to restore the complete symmetry in the disordered phase, and to describe an ordered phase characterized by an order parameter associated with the breaking of the superconductive symmetry.

scholarly journals ANOMALOUS FERMION MASS GENERATION AT THREE LOOPS

2013 ◽  
Vol 28 (22) ◽  
pp. 1350083 ◽  
Author(s):  
APOSTOLOS PILAFTSIS
Keyword(s):  
Gauge Theory ◽  
Quantum Gravity ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Model Building ◽  
Heavy Fermions ◽  
Fermion Mass ◽  
Mass Generation ◽  
Fermion Masses ◽  
Gravity Effects

We present a novel mechanism for generating fermion masses through global anomalies at the three-loop level. In a gauge theory, global anomalies are triggered by the possible existence of scalar or pseudoscalar states and heavy fermions, whose masses may not necessarily result from spontaneous symmetry breaking. The implications of this mass-generating mechanism for model building are discussed, including the possibility of creating low-scale fermion masses by quantum gravity effects.

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