arXiv subjects

Lazaros Tsaloukidis

Publications and source records attributed to Lazaros Tsaloukidis.

6 recordsLinked to original sources

arXiv2026

Curved Odd Elasticity

Living materials such as membranes, cytoskeletal assemblies, cell collectives and tissues can often be described as active solids---materials that are energized from within, with elastic response about a well defined reference configuration. These materials often live in complex and curved manifolds, yet most descriptions of active solids are flat. Here, we explore the interplay between curvature and non-reciprocal elasticity via a covariant effective theory on curved manifolds in combination with numerical simulations. We find that curvature spatially patterns activity, gaps the spectrum, modifies exceptional points and introduces non-Hermitian defect modes. Together these results establish a foundation for hydrodynamic and rheological models on curved manifolds, with direct implications for living matter and active metamaterials.

cond-mat.soft↗

arXiv2025

Non-equilibrium charge-vortex duality

Traditionally applied within equilibrium states, the charge-vortex dualities are expanded to address the complex dynamics of superfluids and ideal fluids under non-static conditions. We have constructed explicit mappings of finite temperature fluid dynamics to gauge theories, enabling a dual description where vortices in both superfluids and ideal fluids are interpreted as charges within these theories. We found that vortices in the normal component naturally exhibit mobility restrictions, as manifested by the symmetries and conservation laws. Next, we formulated the Liénard-Wiechert problem for the ideal fluid at finite temperature and extracted the wave dynamics in the system along with the speed of sound corrections for both fluid components. Finally, we computed the correlation functions for the gauge potentials, particularly elucidating explicit cross-correlations between the normal and superfluid components.

hep-th↗

arXiv2025

Quadrupole gauge theory: anti-Higgs mechanism and elastic dual

Motivated by the duality between elasticity and fracton gauge theory, we study an extension of the gauge group that includes the quadrupole moment. Remarkably, we find that spontaneous breaking of the quadrupole symmetry increases the number of massless excitations. This result appears to challenge the well-established paradigm, according to which gauge fields acquire mass through the Higgs mechanism, and the would-be Goldstone bosons are rendered massive. We refer to this phenomenon as the anti-Higgs mechanism. Furthermore, we demonstrate that the quadrupole gauge theory is dual to an exotic class of elastic systems, which we dub incompressible crystals. The anti-Higgs mechanism in the dual theory corresponds to a phase transition from the incompressible crystal state to an ordinary (compressible) solid.

cond-mat.str-el↗

arXiv2024

Elastic Liénard-Wiechert potentials of dynamical dislocations from tensor gauge theory in 2+1 dimensions

The dynamics of defect excitations in crystalline solids is necessary to understand the macroscopic low-energy properties of elastic media. We use fracton-elasticity duality to systematically study the defect dynamics and interactions in the linear isotropic medium. We derive the explicit expressions for the dual gauge potentials for moving dislocations and the resulting Jefimenko equations. We also compute stresses and strains. The paper includes two physical situations: when the vacancy number is fixed and when the number is fluctuating. If defects are present we show a constraint that needs to be satisfied by them when they climb perpendicularly to their Burgers vector. Next, we extend the classic result of Peach and Koehler for the force between two dislocations and show that, similarly, to moving charges in electrodynamics, it is non-reciprocal, when one dislocation is moving. We argue that our formalism can be extended beyond Cauchy's elasticity by exploiting the simplifications provided by the dual gauge formulation of elastic stresses.

cond-mat.mtrl-sci↗

arXiv2024

Fracton-elasticity duality on curved manifolds

The mechanical properties of crystals on curved substrates mix elastic, geometric and topological degrees of freedom. In order to elucidate the properties of such crystals we formulate the low-energy effective action that combines metric degrees of freedom with displacement fields and defects. We propose dualities for elasticity coupled to curved geometry formulated in terms of tensor gauge theories. We show that the metric degrees of freedom, evolving akin to linearized gravity are mapped to tensors with three indices. When coupled to crystals these degrees of freedom become gapped and, in the presence of dislocations and disclinations, multivalued. The elastic degrees of freedom remain gapless and mapped to symmetric gauge fields with two indices. In analogy with elasticity on flat space formulation we assume that the trace of the total quadrupole moment is conserved. In the dual formulation, topological defects, which act as sources for the gauge fields, are fractons or excitations with restricted mobility. This leads to generalized glide constraints that restrict both displacement and gravitational defects.

hep-th↗

arXiv2023

Twin stars as probes of the nuclear equation of state: effects of rotation through the PSR J0952-0607 pulsar and constraints via the tidal deformability from the GW170817 event

In agreement with the constantly increasing gravitational wave events, new aspects of the internal structure of compact stars can be considered. A scenario in which a first order transition takes place inside these stars is of particular interest as it can lead, under conditions, to a third gravitationally stable branch (besides white dwarfs and neutron stars), the twin stars. The new branch yields stars with the same mass as normal compact stars but quite different radii. In the present work, we focus on hybrid stars undergone a hadron to quark phase transition near their core and how this new stable configuration arises. Emphasis is to be given on the aspects of the phase transition and its parametrization in two different ways, namely with Maxwell and Gibbs construction. We systematically study the gravitational mass, the radius, and the tidal deformability, and we compare them with the predictions of the recent observation by LIGO/VIRGO collaboration, the GW170817 event, along with the mass and radius limits, suggesting possible robust constraints. Moreover, we extent the study in order to include rotation effects on the twin stars configurations. The recent discovery of the fast rotating supermassive pulsar PSR J0952-0607 triggered the effort to constrain the equation of state and moreover to examine possible predictions related to the phase transition in dense nuclear matter. We pay special attention to relate the PSR J0952-0607 pulsar properties with the twin stars predictions and mainly to explore the possibility that the existence of such a massive object would rule out the existence of twin stars. Finally, we discuss the constraints on the radius and mass of the recently observed compact object within the supernova remnant HESS J1731-347. The estimations implies that this object is either the lightest neutron star known, or a star with a more exotic equation of state.

astro-ph.HE↗