Research

In recent years, my research has focussed on various aspects of non-equilibrium effective field theories for many-body systems at finite temperature, and connections to gravity within the context of holographic dualities and string theory.

Quantum Chaos

Effective field theory models for describing the emergence of chaos in quantum many-body systems.

Schwinger-Keldysh Hydrodynamics

An effective field theory formalism for hydrodynamics including stochastic fluctuations.

Active Matter

A hydrodynamic framework for describing temperature and energy fluctuations in active or driven systems.

Higher-Form Symmetries

Hydrodynamics of fluids with string-like and membrane-like extended conserved quantities.

Approximate Symmetries

Hydrodynamics of fluids with weak or approximate symmetries.

Viscoelasticity and Charge-Density Waves

A hydrodynamic framework to describe out-of-equilibrium phenomena in crystals and solids.

Fractons

A new class of physical systems where excitations are not allowed to move once created.

Magneto-hydrodynamics

Hydrodynamics for astrophysical systems such as solar plasma and black hole accretion disks.

Non-Relativistic Hydrodynamics

A new theoretical approach to non-relativistic fluids starting from relativistic fluids.

Holography

Modelling elusive condensed matter systems using higher-dimensional black holes and Einstein's relativity.

Recent Publications

On the temperature of an active nematic
Armas, AJ, LierJun 2025
Resistive relativistic magnetohydrodynamics without Ampère’s law
Lier, AJ, Armas, PorthJan 2025
Fractonic solids
AJJun 2024
Hydrodynamics of thermal active matter
Armas, AJ, LierMay 2024
Higher-group global symmetry and the bosonic M5 brane
Armas, Batzios, AJFeb 2024
Dipole superfluid hydrodynamics. Part II.
AJ, Jensen, Liu, MeffordJan 2024
Schwinger-Keldysh effective field theory for stable and causal relativistic hydrodynamics
AJ, KovtunSep 2023
Dipole superfluid hydrodynamics
AJ, Jensen, Liu, MeffordApr 2023

See my complete list of publications on INSPIRE-HEP database or Google Scholar.