arXiv subjects

Gianbattista-Piero Nicosia

Publications and source records attributed to Gianbattista-Piero Nicosia.

4 recordsLinked to original sources

arXiv2026

Null fluid/gravity correspondence

We construct a new class of perturbative asymptotically Anti-de Sitter pp-wave spacetimes by performing a long-wavelength expansion of Kaigorodov metrics in arbitrary spacetime dimensions. Holographically, these spacetimes are described by a null fluid hydrodynamic expansion around null states in the conformal field theory, which can be obtained as zero temperature and infinite momentum limits of finite temperature states. Building on this, we explicitly show that special cases of this null fluid/gravity correspondence can be obtained as an ultra-relativistic limit of the usual fluid/gravity correspondence in which the temperature tends to zero while the flow approaches the speed of light. We also extend these results to the context of the blackfold approach in which the corresponding pp-wave spacetimes are asymptotically flat and can be obtained as infinite temperature limits of boosted black branes.

hep-th↗

arXiv2025

Null matter and the ultrarelativistic origin of hydrodynamics at zero temperature

We uncover a universal sector of relativistic fluid dynamics by taking a novel ultrarelativistic limit in which the temperature tends to zero while the flow simultaneously approaches the speed of light. In this regime, hydrodynamics becomes an effective theory of \emph{null matter}, characterised by a preferred null vector, a preferred scale, and their gradients. We show that this theory of null matter constitutes an example of a hydrodynamic theory that can be linearly stable and causal in an arbitrary choice of frame. The framework developed here for null matter can offer insights into ultrarelativistic heavy-ion collisions, astrophysical phenomena with inherently large Lorentz factors, and the dynamics of black hole horizons.

hep-th↗

arXiv2024

New asymptotically (Anti)-de Sitter black holes in (super)gravity

We use the duality between gravitational dynamics and fluids living on dynamical surfaces carrying multiple charges, known as the blackfold approach, to perturbativaly construct new asymptotically global (Anti)-de Sitter multi-spinning, non-extremal, multi-charged black holes in theories of higher-dimensional gravity minimally coupled to a dilaton and higher-form gauge fields in spacetime dimensions $D\ge5$, and new asymptotically AdS$_{l}\times S^{m}$ black holes in type IIB and eleven-dimensional supergravity. These solutions include the generalisation of the Kerr-Newman solution to (A)dS carrying either electric or string charge, generalisations of black rings to higher-dimensions with $\mathbb{S}^p\times \mathbb{S}^{n+1}$ horizon topology, static de Sitter solutions carrying arbitrary $q$-brane charge, as well as various asymptotically AdS$_{l}\times S^{m}$ multi-charged and multi-spinning black hole solutions, some of which correspond to novel thermal states in $\mathcal{N}=4$ Super-Yang-Mills theory.

hep-th↗

arXiv2022

Generalised Proca Theories in Teleparallel Gravity

Generalised Proca theories of gravity represent an interesting class of vector-tensor theories where only three propagating degrees of freedom are present. In this work, we propose a new teleparallel gravity analog to Proca theories where the generalised Proca framework is extended due to the lower order nature of torsion based gravity. We develop a new action contribution and explore the example of the Friedmann equations in this regime. We find that teleparallel Proca theories offer the possibility of a much larger class of models in which do have an impact on background cosmology.

gr-qc↗