scholarly journals Crossing antisymmetric Polyakov blocks + dispersion relation

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Apratim Kaviraj
Keyword(s):  
Dispersion Relation ◽  
Global Symmetries ◽  
Correlation Functions ◽  
Sum Rules ◽  
Symmetric Case ◽  
Global Symmetry ◽  
Analytic Functionals ◽  
Antisymmetric Functions

Abstract Many CFT problems, e.g. ones with global symmetries, have correlation functions with a crossing antisymmetric sector. We show that such a crossing antisymmetric function can be expanded in terms of manifestly crossing antisymmetric objects, which we call the ‘+ type Polyakov blocks’. These blocks are built from AdSd+1 Witten diagrams. In 1d they encode the ‘+ type’ analytic functionals which act on crossing antisymmetric functions. In general d we establish this Witten diagram basis from a crossing antisymmetric dispersion relation in Mellin space. Analogous to the crossing symmetric case, the dispersion relation imposes a set of independent ‘locality constraints’ in addition to the usual CFT sum rules given by the ‘Polyakov conditions’. We use the Polyakov blocks to simplify more general analytic functionals in d > 1 and global symmetry functionals.

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.

scholarly journals Gauge-fixed Lattice QCD and the dispersion relation of Wilson fermions

2022 ◽  
Vol 258 ◽  
pp. 02003
Author(s):  
Giuseppe Burgio ◽  
Hannes Vogt
Keyword(s):  
Dispersion Relation ◽  
Lattice Qcd ◽  
Correlation Functions ◽  
Landau Gauge ◽  
Coulomb Gauge ◽  
Tree Level ◽  
Wilson Fermions

We show that, when investigating Wilson-fermions correlation functions on the lattice, one is bound to encounter major difficulties in defining their dispersion relation, even at tree level. The problem is indeed quite general and, although we stumbled upon it while studying Coulomb-gauge applications, it also affects gauge fixed studies in covariant gauges, including their most popular version, Landau gauge. In this paper we will discuss a solution to this problems based on a redefinition of the kinematic momentum of the fermion.

scholarly journals Yet another lesson on the stability conditions in multi-Higgs potentials

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Igor P. Ivanov ◽  
Francisco Vazão
Keyword(s):  
Symmetry Breaking ◽  
Global Symmetries ◽  
Symmetry Group ◽  
Higgs Doublet ◽  
Symmetric Case ◽  
Stability Conditions ◽  
Exact Symmetry ◽  
The Stability ◽  
Necessary And Sufficient

Abstract We discuss a rather common but often unnoticed pitfall which arises when deriving the bounded-from-below (BFB) conditions in multi-Higgs models with softly broken global symmetries. Namely, necessary and sufficient BFB conditions derived for the case with an exact symmetry can be ruined by introducing soft symmetry breaking terms. Using S4 and A4-symmetric three-Higgs-doublet models as an example, we argue that all published necessary and sufficient BFB conditions, even those which are correct for the exactly symmetric case, are no longer sufficient if soft symmetry breaking is added. Using the geometric formalism, we derive the exact necessary and sufficient BFB conditions for the 3HDM with the symmetry group S4, either exact or softly broken, and review the situation for the A4-symmetric case.

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 Anomalous symmetries end at the boundary

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Ryan Thorngren ◽  
Yifan Wang
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Boundary Conditions ◽  
Global Symmetries ◽  
Local Symmetry ◽  
Global Symmetry ◽  
Quantum Field ◽  
Ward Identities ◽  
Diffeomorphism Symmetry ◽  
Gravitational Anomalies

Abstract A global symmetry of a quantum field theory is said to have an ’t Hooft anomaly if it cannot be promoted to a local symmetry of a gauged theory. In this paper, we show that the anomaly is also an obstruction to defining symmetric boundary conditions. This applies to Lorentz symmetries with gravitational anomalies as well. For theories with perturbative anomalies, we demonstrate the obstruction by analyzing the Wess-Zumino consistency conditions and current Ward identities in the presence of a boundary. We then recast the problem in terms of symmetry defects and find the same conclusions for anomalies of discrete and orientation-reversing global symmetries, up to the conjecture that global gravitational anomalies, which may not be associated with any diffeomorphism symmetry, also forbid the existence of boundary conditions. This conjecture holds for known gravitational anomalies in D ≤ 3 which allows us to conclude the obstruction result for D ≤ 4.

scholarly journals QCD sum rules analysis of weak decays of doubly heavy baryons: the $$b\rightarrow c$$ processes

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Zhi-Peng Xing ◽  
Zhen-Xing Zhao
Keyword(s):  
Correlation Functions ◽  
Sum Rules ◽  
Form Factors ◽  
Final States ◽  
Qcd Sum Rules ◽  
Leptonic Decays ◽  
Weak Decays ◽  
Heavy Baryons ◽  
Point Correlation ◽  
Comprehensive Study

AbstractA comprehensive study of $$b\rightarrow c$$ b → c weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the three-point and two-point correlation functions in QCD sum rules. Contributions from up to dimension-6 operators are respectively considered for the two-point and three-point correlation functions. The obtained form factors are then applied to a phenomenological analysis of semi-leptonic decays.

Ward identities and sum rules for composite systems described in the dispersion relation technique

1992 ◽  
Vol 544 (3-4) ◽  
pp. 747-792 ◽  
Author(s):  
V.V. Anisovich ◽  
M.N. Kobrinsky ◽  
D.I. Melikhov ◽  
A.V. Sarantsev
Keyword(s):  
Dispersion Relation ◽  
Sum Rules ◽  
Ward Identities ◽  
Composite Systems
Sign in / Sign up

Export Citation Format

Share Document