arXiv subjects

Pedro Meert

Publications and source records attributed to Pedro Meert.

6 recordsLinked to original sources

arXiv2026

Static and Dynamic perturbations of scalar DBI analogue of a black hole

Perturbations around a spherically symmetric solution of the scalar Dirac-Born-Infeld (DBI) theory obey the equation of motion of a massless scalar field in a curved background with black hole-like properties like finite temperature and an event horizon with zero speed of propagation of information (a black hole analogue). After reviewing some properties of the background geometry for the propagations, we investigate the solutions considering static and dynamic regimes. In the former case we obtain the so-called Love numbers, or more generally scalar polarizability. In the latter case, we employ boundary conditions analogous to the computation of quasi-normal modes, and argue that the background geometry acts as a classical high-pass filter. We therefore provide further evidence that the scalar black hole analogues can be analyzed similarly to a black hole.

hep-th↗

arXiv2026

Coherent quantum geometry: de Sitter spacetime in different foliations

In any theory of quantum gravity, an interesting question to address is to what extent known solutions of the Einstein field equations can be obtained as expectation values of metric operators on suitable quantum states. In this work, we consider coherent states (to ensure minimum uncertainty) for different foliations of the de~Sitter spacetime and study temporal evolution and coordinate invariance. A general framework will first be introduced for metrics that can be diagonalised globally. We will then find that the normalisability of coherent states in this framework requires using reference frames without coordinate singularities.

gr-qc↗

arXiv2025

Quantum maximally symmetric space-times

We show that 4-dimensional maximally symmetric spacetimes can be obtained from a coherent state quantisation of gravity, always resulting in geometries that approach the Minkowski vacuum exponentially away from the radius of curvature. A possible connection with the central charge in the AdS/CFT correspondence is also noted.

gr-qc↗

arXiv2024

Rotational holographic transport from KN-AdS black hole

We consider rotational holographic transport in strongly coupled 2+1 dimensional systems, from the point of view of 3+1 dimensional gravity. We consider the moment of inertia $I$ as a kind of transport coefficient, identified with the moment of inertia of a charged rotating black hole in $AdS_4$ background. In the low-temperature region, we find the behaviour of the density $I/A$ with temperature $T$ and angular velocity $\Omega$, and find a quadratic behaviour for $\partial(I/A)/\partial\Omega$ with $T$, in the presence of some charge $Q$.

hep-th↗

arXiv2022

Transport coefficients associated to black holes on the brane: analysis of the shear viscosity-to-entropy density ratio

In this thesis, we apply the AdS/CFT correspondence to space-times associated with extensions of General Relativity. We are particularly interested in calculating the transport coefficient, the shear viscosity, associated with the effective field theory whose dual is a black hole space-time in bulk. The correspondence also allows us to compute thermodynamic quantities, in which the entropy, plays a prominent role when the ratio between the shear viscosity-to-entropy density is taken. This ratio is conjectured to have a minimum value of $1/4{\pi}$, in natural units. The main results presented in this thesis consist of calculating the ratio for two different cases, and then applying the KSS conjecture - which establishes the minimum value for the ratio -, to investigate properties associated with the deformed space-time metrics. A brief review of General Relativity and Black Holes is presented. The so-called Brane World formalism is introduced, obtaining the equivalent of Einstein's equations and Black Hole solutions on the brane, which can be seen as extensions of solutions known in General Relativity. We discuss the formulation of AdS/CFT correspondence, and how to apply it to compute transport coefficients. Then applying this knowledge to compute transport coefficients associated with the solutions constituting an extension of General Relativity. Naturally, throughout the process of developing this work other interesting questions arise, therefore we include two studies related to these developments. In one we investigate the computation of transport coefficients when we have a fermionic sector in the model. The second is a proposal on how to evaluate the consistency of AdS/CFT correspondence via the calculation of the Weyl anomaly.

hep-th↗

arXiv2021

Gravitational decoupling, hairy black holes and conformal anomalies

Hairy black holes in the gravitational decoupling setup are studied from the perspective of conformal anomalies. Fluctuations of decoupled sources can be computed by measuring the way the trace anomaly-to-holographic Weyl anomaly ratio differs from unit. Therefore the gravitational decoupling parameter governing three hairy black hole metrics is then bounded to a range wherein one can reliably emulate AdS/CFT with gravitational decoupled solutions, in the tensor vacuum regime.

hep-th↗