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André H. Gomes

Publications and source records attributed to André H. Gomes.

7 recordsLinked to original sources
arXiv2025

Probing emergent axion electrodynamics with waveguide apparatus

We demonstrate that a conventional hollow conductor waveguide filled with a material exhibiting the coexistence of chiral magnetic and anomalous quantum Hall effects supports the propagation of transverse electromagnetic modes. This simple setup provides a direct and optically feasible method to probe the simultaneous presence of these phenomena, potentially enabling the detection of an emergent axion-like field within condensed matter systems.

cond-mat.mes-hall↗
arXiv2023

Remarks on the quasi-position representation in models of generalized uncertainty principle

This note aims to elucidate certain aspects of the quasi-position representation frequently used in the investigation of one-dimensional models based on the generalized uncertainty principle (GUP). We specifically focus on two key points: (i) Contrary to recent claims, the quasi-position operator can possess physical significance even though it is non-Hermitian, and (ii) in the quasi-position representation, operators associated with the position, such as the potential energy, also behave as a derivative operator on the quasi-position coordinate, unless the method of computing expectation values is modified. The development of both points revolves around the observation that the position and quasi-position operators share the same set of eigenvalues and are connected through a non-unitary canonical transformation. This outcome may have implications for widely referenced constraints on GUP parameters.

quant-ph↗
arXiv2023

On the algebraic approach to GUP in anisotropic space

Motivated by current searches for signals of Lorentz symmetry violation in nature and recent investigations on generalized uncertainty principle (GUP) models in anisotropic space, in this paper we identify GUP models satisfying two criteria: (i) invariance of commutators under canonical transformations, and (ii) physical independence of position and momentum on the ordering of auxiliary operators in their definitions. Compliance of these criteria is fundamental if one wishes to unambiguously describe GUP using an algebraic approach but, surprisingly, neither is trivially satisfied when GUP is assumed within anisotropic space. As a consequence, we use these criteria to place important restrictions on what or how GUP models may be approached algebraically.

quant-ph↗
arXiv2022

Constraining GUP Models Using Limits on SME Coefficients

Generalized uncertainty principles (GUP) and, independently, Lorentz symmetry violations are two common features in many candidate theories of quantum gravity. Despite that, the overlap between both has received limited attention so far. In this brief paper, we carry out further investigations on this topic. At the nonrelativistic level and in the realm of commutative spacetime coordinates, a large class of both isotropic and anisotropic GUP models is shown to produce signals experimentally indistinguishable from those predicted by the Standard Model Extension (SME), the common framework for studying Lorentz-violating phenomena beyond the Standard Model. This identification is used to constrain GUP models using current limits on SME coefficients. In particular, bounds on isotropic GUP models are improved by a factor of $10^{7}$ compared to current spectroscopic bounds and anisotropic models are constrained for the first time.

hep-th↗
arXiv2022

Constraining GUP Models Using Limits on SME Coefficients

In this proceedings, I outline recent efforts to constrain models based on generalized uncertainty principles (GUP) using limits on coefficients of the Standard-Model Extension. Two main results are reported: (1) bounds on isotropic GUP models are improved by a factor of $10^{10}$ compared to previous spectroscopic bounds; and (2) anisotropic GUP models are established and also constrained.

hep-ph↗
arXiv2013

No one-loop gauge anomalies for a Lorentz-violating quantum electrodynamics: Evaluation of the three-photon vertex

Identification of the diagrams that can lead to gauge anomalies in the (minimal) Lorentz- and $CPT$-violating extension of quantum electrodynamics reveals these are the electron self-energy and vertex correction (related to the Ward-Takahashi identity), the photon self-energy (related to the vacuum polarization tensor transversality), and the three-photon vertex diagrams. All but the latter were explicitly verified to be free of anomalies to first order in loop expansion. Here we provide this remaining evaluation and verify the absence of anomalies in this process.

hep-th↗