scholarly journals Hydrodynamic effective field theory and the analyticity of hydrostatic correlators

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Akash Jain ◽  
Pavel Kovtun ◽  
Adam Ritz ◽  
Ashish Shukla
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Correlation Functions ◽  
Longitudinal Velocity ◽  
Effective Field ◽  
Density Fluctuations ◽  
Relativistic Hydrodynamics ◽  
Finite Frequency ◽  
Sound Modes ◽  
Theory Framework

Abstract We study one-loop corrections to retarded and symmetric hydrostatic correlation functions within the Schwinger-Keldysh effective field theory framework for relativistic hydrodynamics, focusing on charge diffusion. We first consider the simplified setup with only diffusive charge density fluctuations, and then augment it with momentum fluctuations in a model where the sound modes can be ignored. We show that the loop corrections, which generically induce non-analyticities and long-range effects at finite frequency, non-trivially preserve analyticity of retarded correlation functions in spatial momentum due to the KMS constraint, as a manifestation of thermal screening. For the purposes of this analysis, we develop an interacting field theory for diffusive hydrodynamics, seen as a limit of relativistic hydrodynamics in the absence of temperature and longitudinal velocity fluctuations.

scholarly journals Effective field theory for hydrodynamics without boosts

2021 ◽  
Vol 11 (3) ◽  
Author(s):  
Jácome Armas ◽  
Akash Jain
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Fluid Velocity ◽  
Transport Coefficients ◽  
Effective Field ◽  
Covariant Formulation ◽  
Diffusion Mode ◽  
Sound Modes ◽  
Shear Modes ◽  
Theory Framework

We formulate the Schwinger-Keldysh effective field theory of hydrodynamics without boost symmetry. This includes a spacetime covariant formulation of classical hydrodynamics without boosts with an additional conserved particle/charge current coupled to Aristotelian background sources. We find that, up to first order in derivatives, the theory is characterised by the thermodynamic equation of state and a total of 29 independent transport coefficients, in particular, 3 hydrostatic, 9 non-hydrostatic non-dissipative, and 17 dissipative. Furthermore, we study the spectrum of linearised fluctuations around anisotropic equilibrium states with non-vanishing fluid velocity. This analysis reveals a pair of sound modes that propagate at different speeds along and opposite to the fluid flow, one charge diffusion mode, and two distinct shear modes along and perpendicular to the fluid velocity. We present these results in a new hydrodynamic frame that is linearly stable irrespective of the boost symmetry in place. This provides a unified covariant stable approach for simultaneously treating Lorentzian, Galilean, and Lifshitz fluids within an effective field theory framework and sets the stage for future studies of non-relativistic intertwined patterns of symmetry breaking.

scholarly journals Extremal correlators and random matrix theory

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Alba Grassi ◽  
Zohar Komargodski ◽  
Luigi Tizzano
Keyword(s):  
Field Theory ◽  
Gauge Theory ◽  
Matrix Model ◽  
Effective Field Theory ◽  
Random Matrix ◽  
Correlation Functions ◽  
Matrix Theory ◽  
Effective Field ◽  
Random Matrix Model ◽  
Large Charge

Abstract We study the correlation functions of Coulomb branch operators of four-dimensional $$ \mathcal{N} $$ N = 2 Superconformal Field Theories (SCFTs). We focus on rank-one theories, such as the SU(2) gauge theory with four fundamental hypermultiplets. “Extremal” correlation functions, involving exactly one anti-chiral operator, are perhaps the simplest nontrivial correlation functions in four-dimensional Quantum Field Theory. We show that the large charge limit of extremal correlators is captured by a “dual” description which is a chiral random matrix model of the Wishart-Laguerre type. This gives an analytic handle on the physics in some particular excited states. In the limit of large random matrices we find the physics of a non-relativistic axion-dilaton effective theory. The random matrix model also admits a ’t Hooft expansion in which the matrix is taken to be large and simultaneously the coupling is taken to zero. This explains why the extremal correlators of SU(2) gauge theory obey a nontrivial double scaling limit in states of large charge. We give an exact solution for the first two orders in the ’t Hooft expansion of the random matrix model and compare with expectations from effective field theory, previous weak coupling results, and we analyze the non-perturbative terms in the strong ’t Hooft coupling limit. Finally, we apply the random matrix theory techniques to study extremal correlators in rank-1 Argyres-Douglas theories. We compare our results with effective field theory and with some available numerical bootstrap bounds.

scholarly journals Non-equilibrium effective field theory and second sound

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Michael J. Landry
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Sound Wave ◽  
Effective Field ◽  
Second Sound ◽  
Gauge Symmetries ◽  
Sound Modes ◽  
State Of Matter ◽  
The Difference ◽  
Non Equilibrium

Abstract We investigate the phenomenon of second sound in various states of matter from the perspective of non-equilibrium effective field theory (EFT). In particular, for each state of matter considered, we find that at least two (though sometimes multiple) qualitatively different EFTs exist at finite temperature such that there is always at least one EFT with a propagating second-sound wave and at least one with no such second-sound wave. To aid in the construction of these EFTs, we use the method of cosets developed for non-equilibrium systems. It turns out that the difference between the EFTs with and without second-sound modes can be understood as arising from different choices of a new kind of inverse Higgs constraint. Finally, we demonstrate that it is possible to bypass the need for new inverse Higgs constraints by formulating EFTs on a new kind of manifold that is like the usual fluid worldvolume, but with reduced gauge symmetries.

scholarly journals Three and four harmonically trapped particles in an effective-field-theory framework

2010 ◽  
Vol 82 (3) ◽  
Author(s):  
J. Rotureau ◽  
I. Stetcu ◽  
B. R. Barrett ◽  
M. C. Birse ◽  
U. van Kolck
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Effective Field ◽  
Trapped Particles ◽  
Theory Framework

scholarly journals Probing the nonunitarity of the leptonic mixing matrix at the CEPC

2016 ◽  
Vol 31 (33) ◽  
pp. 1644006 ◽  
Author(s):  
Stefan Antusch ◽  
Oliver Fischer
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Effective Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Neutrino Masses ◽  
Performance Parameters ◽  
The Standard Model ◽  
Mixing Matrix ◽  
Theory Framework

The nonunitarity of the leptonic mixing matrix is a generic signal of new physics aiming at the generation of the observed neutrino masses. We discuss the Minimal Unitarity Violation (MUV) scheme, an effective field theory framework which represents the class of extensions of the Standard Model (SM) by heavy neutral leptons, and discuss the present bounds on the nonunitarity parameters as well as estimates for the sensitivity of the CEPC, based on the performance parameters from the preCDR.

scholarly journals Multi-track displaced vertices at B-factories

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Mason Acevedo ◽  
Albany Blackburn ◽  
Nikita Blinov ◽  
Brian Shuve ◽  
Mavis Stone
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Large Range ◽  
Effective Field ◽  
Higgs Bosons ◽  
Approximate Symmetries ◽  
Low Background ◽  
Hidden Sector ◽  
Displaced Vertex ◽  
Theory Framework

Abstract We propose a program at B-factories of inclusive, multi-track displaced vertex searches, which are expected to be low background and give excellent sensitivity to non-minimal hidden sectors. Multi-particle hidden sectors often include long-lived particles (LLPs) which result from approximate symmetries, and we classify the possible decays of GeV-scale LLPs in an effective field theory framework. Considering several LLP production modes, including dark photons and dark Higgs bosons, we study the sensitivity of LLP searches with different number of displaced vertices per event and track requirements per displaced vertex, showing that inclusive searches can have sensitivity to a large range of hidden sector models that are otherwise unconstrained by current or planned searches.

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