arXiv subjects

Jackson Wu

Publications and source records attributed to Jackson Wu.

7 recordsLinked to original sources

arXiv2023

Relativistic Hydrodynamics under Rotation: Prospects & Limitations from a Holographic Perspective

The AdS/CFT correspondence, or holography, has provided numerous important insights into the behavior of strongly-coupled many-body systems. Crucially, it has provided a testing ground for the construction of new effective field theories, especially those in the low frequency, long wavelength limit known as hydrodynamics. We review the study of strongly-coupled rotating fluids using holography, and we examine the hydrodynamics emerging from the study of rotating Myers-Perry black holes. We discuss three regimes in which holographic rotating fluids display either (1) hydrodynamic behavior of a boosted fluid, (2) hydrodynamic behavior distinct from a boosted fluid, or (3) no obvious hydrodynamic behavior. We describe techniques to obtain hydrodynamic and non-hydrodynamic modes, and we compute the radius of convergence for the hydrodynamic regimes. The limitations of hydrodynamics under rotation are discussed alongside our findings.

hep-th↗

arXiv2020

Chiral hydrodynamics in strong external magnetic fields

We construct the general hydrodynamic description of (3+1)-dimensional chiral charged (quantum) fluids subject to a strong external magnetic field with effective field theory methods. We determine the constitutive equations for the energy-momentum tensor and the axial charge current, in part from a generating functional. Furthermore, we derive the Kubo formulas which relate two-point functions of the energy-momentum tensor and charge current to 27 transport coefficients: 8 independent thermodynamic, 4 independent non-dissipative hydrodynamic, and 10 independent dissipative hydrodynamic transport coefficients. Five Onsager relations render 5 more transport coefficients dependent. We uncover four novel transport effects, which are encoded in what we call the shear-induced conductivity, the two expansion-induced longitudinal conductivities and the shear-induced Hall conductivity. Remarkably, the shear-induced Hall conductivity constitutes a novel non-dissipative transport effect. As a demonstration, we compute all transport coefficients explicitly in a strongly coupled quantum fluid via holography.

hep-th↗

arXiv2018

Universal magnetoresponse in QCD and $\mathcal{N}=4$ SYM

Using recent lattice data on the thermodynamics of QCD in the presence of a background magnetic field, we show that the ratio of transverse to longitudinal pressure exhibits, to good accuracy, a simple scaling behavior over a wide range of temperature and magnetic field, essentially depending only on the ratio $T/\sqrt B$. We compare this QCD response to the corresponding magnetoresponse in maximally supersymmetric Yang Mills theory. Given suitable calibrations defining the comparison, we find excellent agreement. This may be viewed as a further test of the applicability of holographic models for hot QCD.

hep-th↗

arXiv2017

Quasinormal modes of charged magnetic black branes & chiral magnetic transport

We compute quasinormal modes (QNMs) of the metric and gauge field perturbations about black branes electrically and magnetically charged in the Einstein-Maxwell-Chern-Simons theory. By the gauge/gravity correspondence, this theory is dual to a particular class of field theories with a chiral anomaly, in a thermal charged plasma state subjected to a constant external magnetic field, $B$. The QNMs are dual to the poles of the two-point functions of the energy-momentum and axial current operators, and they encode information about the dissipation and transport of charges in the plasma. Complementary to the gravity calculation, we work out the hydrodynamic description of the dual field theory in the presence of a chiral anomaly, and a constant external $B$. We find good agreement with the weak field hydrodynamics, which can extend beyond the weak $B$ regime into intermediate regimes. Furthermore, we provide results that can be tested against thermodynamics and hydrodynamics in the strong $B$ regime. We find QNMs exhibiting Landau level behavior, which become long-lived at large $B$ if the anomaly coefficient exceeds a critical magnitude. Chiral transport is analyzed beyond the hydrodynamic approximation for the five (formerly) hydrodynamic modes, including a chiral magnetic wave.

hep-th↗

arXiv2013

A Holographic Model of the Kondo Effect

We propose a model of the Kondo effect based on the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, also known as holography. The Kondo effect is the screening of a magnetic impurity coupled anti-ferromagnetically to a bath of conduction electrons at low temperatures. In a (1+1)-dimensional CFT description, the Kondo effect is a renormalization group flow triggered by a marginally relevant (0+1)-dimensional operator between two fixed points with the same Kac-Moody current algebra. In the large-N limit, with spin SU(N) and charge U(1) symmetries, the Kondo effect appears as a (0+1)-dimensional second-order mean-field transition in which the U(1) charge symmetry is spontaneously broken. Our holographic model, which combines the CFT and large-N descriptions, is a Chern-Simons gauge field in (2+1)-dimensional AdS space, AdS3, dual to the Kac-Moody current, coupled to a holographic superconductor along an AdS2 subspace. Our model exhibits several characteristic features of the Kondo effect, including a dynamically generated scale, a resistivity with power-law behavior in temperature at low temperatures, and a spectral flow producing a phase shift. Our holographic Kondo model may be useful for studying many open problems involving impurities, including for example the Kondo lattice problem.

hep-th↗

arXiv2009

Non-Supersymmetric New Physics from Moeller Scattering

We study in an effective operator approach how the effects of new physics from various scenarios containing extra $Z'$ gauge bosons or doubly charged scalars can affect, and thus be tested by the precision polarized Moeller scattering experiment. We give Wilson coefficients for various classes of models, and we deduce constraints on the parameter space of the relevant coupling constants and mixing angles from the results of the SLAC E158 experiment, and that projected from the future high precision JLAB experiment.

hep-ph↗

arXiv2008

Cold Nuclear Matter In Holographic QCD

We study the Sakai-Sugimoto model of holographic QCD at zero temperature and finite chemical potential. We find that as the baryon chemical potential is increased above a critical value, there is a phase transition to a nuclear matter phase characterized by a condensate of instantons on the probe D-branes in the string theory dual. As a result of electrostatic interactions between the instantons, this condensate expands towards the UV when the chemical potential is increased, giving a holographic version of the expansion of the Fermi surface. We argue based on properties of instantons that the nuclear matter phase is necessarily inhomogeneous to arbitrarily high density. This suggests an explanation of the "chiral density wave" instability of the quark Fermi surface in large N_c QCD at asymptotically large chemical potential. We study properties of the nuclear matter phase as a function of chemical potential beyond the transition and argue in particular that the model can be used to make a semi-quantitative prediction of the binding energy per nucleon for nuclear matter in ordinary QCD.

hep-th↗