arXiv subjects

R. da Rocha

Publications and source records attributed to R. da Rocha.

At least 37 records · Page 2Linked to original sources

arXiv2023

Thermodynamic and configurational entropy of quantum Schwarzschild geometries

We study different entropies for coherent states representing the geometry of spherically symmetric compact systems. We show that the thermodynamic entropy reproduces the Bekenstein-Hawking result in the presence of thermal modes at the Hawking temperature if the object is a black hole and saturates the Bekenstein bound for more general compact objects. We also analyse the information entropy of the quantum coherent state without radiation and find further support against the singular Schwarzschild geometry.

gr-qc↗

arXiv2023

Configurational information measure of mesonic states in 4-flavor AdS/QCD

Strange axial-vector kaons, $K_1$, and $f_1$ meson resonances are investigated in the 4-flavor AdS/QCD model. Their underlying differential configurational entropy is computed and the mass spectra of higher-excited resonances, in both these mesonic families, are achieved and discussed. This technique merges the 4-flavor AdS/QCD and experimental data regarding the mass spectrum of $K_1$ and $f_1$ meson resonances that have been already detected and reported in the Particle Data Group, also bringing forth a route to explore physical features of the next generation of resonances in the $K_1$ and $f_1$ meson families.

hep-ph↗

arXiv2023

Axion stars in MGD background

The minimal geometric deformation (MGD) paradigm is here employed to survey axion stars on fluid branes. The finite value of the brane tension provides beyond-general relativity corrections to the density, compactness, radius, and asymptotic limit of the gravitational mass function of axion stars, in a MGD background. The brane tension also enhances the effective range and magnitude of the axion field coupled to gravity. MGD axion stars are compatible to mini-massive compact halo objects for almost all the observational range of brane tension, however, a narrow range allows MGD axion star densities large enough to produce stimulated decays of the axion to photons, with no analogy in the general-relativistic (GR) limit. Besides, the gravitational mass and the density of MGD axion stars are shown to be up to four orders of magnitude larger than the GR axion stars, being also less sensitive to tidal disruption events under collision with neutron stars, for lower values of the fluid brane tension.

hep-th↗

arXiv2023

Fermionic dark matter-photon quantum interaction: A mechanism for darkness

Mass dimension one fermionic fields are prime candidates to describe dark matter, due to their intrinsic neutral nature, as they are constructed as eigenstates of the charge conjugation operator with dual helicity. To formulate the meaning of the darkness, the fermion-photon coupling is scrutinized with a Pauli-like interaction, and the path integral is then formulated from the phase space constraint structure. Ward-Takahashi-like identities and Schwinger-Dyson equations, together with renormalizability, are employed to investigate a phenomenological mechanism to avoid external light signals. Accordingly, the non-polarized pair annihilation and Compton-like processes are shown to vanish at the limit of small scattering angles even if considering 1-loop radiative corrections, reinforcing the dark matter interpretation. However, dark matter interactions with nucleons are still possible. Motivated by recent nucleon-recoil experiments to detect dark matter, we furnish a consistent theoretical setup to describe interaction with the photon compatible with the prevalence of darkness.

hep-ph↗

arXiv2022

Configurational entropy of generalized sine-Gordon-type models

A family of deformed models of the sine-Gordon-type can be generated by twisting the sine-Gordon model. As a particular case, the 3-sine-Gordon model is here addressed, whose differential configurational entropy and the differential configurational complexity of three topological sectors are discussed, using two complementary approaches. Stability aspects are also discussed.

hep-th↗

arXiv2022

Configurational entropy of black hole quantum cores

Two types of information entropy are studied for the quantum states of a model for the matter core inside a black hole geometry. A detailed description is first given of the quantum mechanical picture leading to a spectrum of bound states for a collapsing ball of dust in general relativity with a non-trivial ground state. Information entropies are then computed, shedding new light on the stability of the ground state and the spectrum of higher excited states.

gr-qc↗

arXiv2022

Echoes of the gravitational decoupling: scalar perturbations and quasinormal modes of hairy black holes

The behavior of hairy black hole solutions, obtained by the gravitational decoupling (GD) method, is investigated under scalar perturbations. The quasinormal mode frequencies of such solutions are regulated by GD hair. The numerically generated wave solutions are derived for a range of values for the GD hairy black hole parameters, with higher-frequency modes very sensitive to them. The results are confronted with the corresponding ones for the Schwarzschild solution, whose deviations from it demonstrate a unique physical identification of GD hairy black holes. The method here presented comprises the first steps towards the obtainment of the observable signature of GD hairy black holes at ground-based detectors, emitted from coalescing binary systems of GD hairy black hole mergers in the ringdown phase.

gr-qc↗

arXiv2022

Gravitational collapse in AdS: instabilities, turbulence, and information

The gravitational collapse in asymptotically AdS spacetimes is studied, using the differential configurational entropy (DCE). The DCE is shown to comply with the instability of the Einstein-Klein-Gordon system, leading to different stages in the route to turbulence and final black hole formation, including near the critical behavior.

hep-th↗

arXiv2022

Nuclear information entropy, gravitational form factor, and glueballs in AdS/QCD

The nuclear configurational entropy (NCE) is employed to derive two parameters encoding the Pomeron Regge trajectory and the spectrum of closed strings, which are also related to the glueball mass, precisely matching data of the TOTEM collaboration at the LHC. In the Regge regime of holographic QCD, the (Reggeized) glueball propagator and the gravitational form factor of the proton occupy a relevant spot in AdS/QCD. They are used for deriving the cross-sections for the TeV scale proton-proton scattering process, which are the main ingredient for computing the NCE. The nuclear configurational stability is also addressed.

hep-ph↗

arXiv2022

Fermionic dark matter interaction with the photon and the proton in the quantum field-theoretical approach and generalizations

Mass dimension one quantum fields, constructed upon eigenspinors of the charge conjugation operator with dual helicity (ELKO), are prime candidates to describe dark matter. Their interaction with the photon and the proton, in scattering processes, are here explored and discussed, using both the standard QFT with a Maxwell gauge field and a generalized QFT also involving a Podolsky gauge sector. Renormalization and radiative corrections are analyzed in the ELKO setup, in the context of a generalized spinor dual and the twisted conjugation, both yielding unitarity. Several applications are scrutinized, involving the inherent darkness underlying ELKO construction and galaxies rotation curves, the non-relativistic potential regime, and the Møller-like scattering involving ELKO.

hep-th↗

arXiv2022

Configurational entropy and spectroscopy of pomeron resonances in dynamical AdS/QCD

Pomeron resonances in AdS/QCD are here studied using the configurational entropy (CE). The concept of CE Regge trajectories, associating the CE of the pomeron resonances with both their spin $J^{PC}$ and to their mass spectra, is used to derive the mass spectra of higher $J^{PC}$ pomeron resonances. For it, the linear, the exponential modified and the anomalous quadratic dilatonic models, each one with linear and logarithmic anomalous corrections, are employed. Several methods are implemented, hybridizing AdS/QCD and established data of lattice QCD.

hep-th↗

arXiv2022

Differential configurational entropy and the gravitational collapse of a kink

The gravitational instability of kinks is scrutinized in the context of information entropy, including the black hole formation near the scalar field critical collapse. The differential configurational entropy (DCE) is computed and examined for globally perturbed static kinks and the far-from-equilibrium kink solutions as well. In the case of the first kink, the DCE determines a critical value of the perturbation parameter regulating points of bifurcation that characterize a phase transition, whose supercritical range leads to collapse and subsequent black hole formation. For the far-from-equilibrium kink solutions, the DCE supports black hole formation.

hep-th↗

arXiv2021

Generalized Navier-Stokes equations and soft hairy horizons in fluid/gravity correspondence

The fluid/gravity correspondence establishes how gravitational dynamics, as dictated by Einstein's field equations, are related to the fluid dynamics, governed by the relativistic Navier-Stokes equations. In this work the correspondence is extended, where the duality between incompressible fluids and gravitational backgrounds with soft hair excitations is implemented. This construction is set through appropriate boundary conditions to the gravitational background, leading to a correspondence between generalized incompressible Navier-Stokes equations and soft hairy horizons.

hep-th↗

arXiv2021

Configurational entropy of heavy-quark QCD exotica: engendering the next generation

The mass spectroscopy of exotic meson states is scrutinized in the AdS/QCD paradigm. The differential configurational entropy is then used to study, derive, and analyze the mass spectrum of excited exotic vector meson resonances, whose configurational stability is also addressed. For it the hadronic molecule, the hadrocharmonium, and the hybrid description of heavy-quark exotic mesonic states are employed to more precisely match experimental data in the Particle Data Group and also to predict the next generations of heavy-quark QCD exotica in the $Z_c$, $Y$, $π_1$, and $Z_b$ exotic meson families.

hep-ph↗

arXiv2021

Information in AdS/QCD: mass spectroscopy of isovector mesons

The mass spectra of isovector $Υ$, $ψ$, $ϕ$, and $ω$ meson resonances are investigated, in the AdS/QCD and information entropy setups. The differential configurational entropy is employed to obtain the mass spectra of radial $S$-wave resonances, with higher excitation levels, in each one of these meson families, whose respective first undisclosed states are discussed and matched up to candidates in the Particle Data Group.

hep-ph↗

arXiv2021

Probing the minimal geometric deformation with trace and Weyl anomalies

The method of minimal geometric deformation (MGD) is used to derive static, strongly gravitating, spherically symmetric, compact stellar distributions. The trace and Weyl anomalies are then employed to probe the MGD in the holographic setup, as a realistic model, playing a prominent role in AdS/CFT.

gr-qc↗

arXiv2021

Additional fermionic fields onto parallelizable 7-spheres

The geometric Fierz identities are here employed to generate new emergent fermionic fields on the parallelizable (curvatureless, torsionfull) 7-sphere ($S^7$). Employing recently found new classes of spinor fields on the $S^7$ spin bundle, new classes of fermionic fields are obtained from their bilinear covariants by a generalized reconstruction theorem, on the parallelizable $S^7$. Using a generalized non-associative product on the octonionic bundle on the parallelizable $S^7$, these new classes of algebraic spinor fields, lifted onto the parallelizable $S^7$, are shown to correctly transform under the Moufang loop generators on $S^7$.

hep-th↗

arXiv2020

Odd-spin glueballs, AdS/QCD and information entropy

Odd-spin glueballs in the dynamical AdS/QCD model are scrutinized, in the paradigm of the configurational entropy (CE). Configurational-entropic Regge trajectories, that relate the CE underlying odd-spin glueballs to their mass spectra and spin, are then engendered. They predict the mass spectra of odd-spin glueballs, besides pointing towards the configurational stability of odd-spin glueball resonances. The exponential modified dilaton with logarithmic anomalous dimensions comprises the most suitable choice to derive the mass spectra of odd-spin glueballs, compatible to lattice QCD. It is then used in a hybrid paradigm that takes both lattice QCD and the AdS/QCD correspondence into account.

hep-th↗