A5051768256- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Noncommutative and Quantum Gravity Theories
- Pulsars and Gravitational Waves Research
- Quantum Electrodynamics and Casimir Effect
- Relativity and Gravitational Theory
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Particle physics theoretical and experimental studies
- Geophysics and Gravity Measurements
- Advanced Differential Geometry Research
- Solar and Space Plasma Dynamics
- Quantum Mechanics and Applications
- Geophysics and Sensor Technology
- Advanced Thermodynamics and Statistical Mechanics
- Liver Disease and Transplantation
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Quantum and Classical Electrodynamics
- Mechanical and Optical Resonators
- Nonlinear Waves and Solitons
- Quantum Mechanics and Non-Hermitian Physics
- Advanced Mathematical Theories and Applications
- Algebraic and Geometric Analysis
- Statistical Mechanics and Entropy
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2016-2025
University of Bologna
2016-2025
Osservatorio astronomico di Bologna
2016-2025
Istituto Nazionale di Fisica Nucleare
2004-2025
Applied Mathematics (United States)
2025
Mater Research
2025
Aristotle University of Thessaloniki
2023
Russian Academy of Sciences
2022
Loyola Marymount University
2022
Institute of Space Science - INFLPR Subsidiary
2021-2022
We investigate the extension of isotropic interior solutions for static self-gravitating systems to include effects anisotropic spherically symmetric gravitational sources by means decoupling realised via minimal geometric deformation approach. In particular, matching conditions at surface star with outer Schwarzschild space-time are studied in great detail, and we describe how generate, from a single physically acceptable solution, new families whose physical acceptability is also inherited...
We compute the corrections to Schwarzschild metric necessary reproduce Hawking temperature derived from a generalized uncertainty principle (GUP), so that GUP deformation parameter is directly linked of metric. Using this modified metric, we standard general relativistic predictions for light deflection and perihelion precession, both planets in solar system binary pulsars. This analysis allows us set bounds well-known astronomical measurements.
The minimal geometric deformation approach was introduced in order to study the exterior spacetime around spherically symmetric self-gravitating systems, such as stars or similar astrophysical objects, Randall–Sundrum brane-world framework. A consistent extension of this is developed here, which contains modifications both time component and radial a metric. modified Schwarzschild geometry obtained an example its simplest application, new solution that potentially useful describe also presented.
We investigate how a spherically symmetric fluid modifies the Schwarzschild vacuum solution when there is no exchange of energy-momentum between and central source metric. This system described by means gravitational decoupling realised via minimal geometric deformation approach, which allows us to prove that must be anisotropic. Several cases are then explicitly shown.
General Relativity and the $\Lambda$CDM framework are currently standard lore constitute concordance paradigm. Nevertheless, long-standing open theoretical issues, as well possible new observational ones arising from explosive development of cosmology last two decades, offer motivation lead a large amount research to be devoted in constructing various extensions modifications. All extended theories scenarios first examined under light consistency, then applied geometrical backgrounds, such...
Abstract We employ the gravitational decoupling approach for static and spherically symmetric systems to develop a simple powerful method in order (a) continuously isotropize any anisotropic solution of Einstein field equations, (b) generate new solutions self-gravitating distributions with same or vanishing complexity factor. A few working examples are given illustrative purposes.
We introduce a systematic and direct procedure to generate hairy rotating black holes by deforming spherically symmetric seed solution. develop our analysis in the context of gravitational decoupling approach, without resorting Newman-Janis algorithm. As examples possible applications, we investigate how Kerr hole solution is modified surrounding fluid with conserved energy-momentum tensor. find non-trivial extensions Kerr-Newman primary hair. prove that charged can have same horizon as...
Abstract The horizon is a classical concept that arises in general relativity and therefore not clearly defined when the source cannot be reliably described by physics. To any (sufficiently) localised quantum mechanical wavefunction, one can associate wavefunction which yields probability of finding given radius centred around source. We then to each particle it black hole, existence minimum hole mass follows naturally, agrees with obtained from hoop conjecture Heisenberg uncertainty principle.
It is known that the Einstein field equations in five dimensions admit more general spherically symmetric black holes on brane than four-dimensional relativity. We propose two families of analytic solutions (with ${g}_{\mathrm{tt}}\ensuremath{\ne}\ensuremath{-}{g}_{\mathrm{rr}}^{\ensuremath{-}1}),$ parametrized by Arnowitt-Deser-Misner mass and post-Newtonian parameter $\ensuremath{\beta},$ which reduce to Schwarzschild for $\ensuremath{\beta}=1.$ Agreement with observations requires...
The minimal geometric deformation approach is employed to show the existence of brane-world stellar distributions with a vacuum Schwarzschild exterior, thus without energy leaking from exterior star into extra dimension. interior satisfies all elementary criteria physical acceptability for solution, namely, it regular at origin, pressure and density are positive decrease monotonically increasing radius, conditions fulfilled. A very thin solid crust negative radial separates having thickness...
We consider a solution of the effective four-dimensional Einstein equations, obtained from general relativistic Schwarzschild metric through principle Minimal Geometric Deformation (MGD). Since brane tension can, in general, introduce new singularities on Eötvös model MGD framework, we require absence observed singularities, order to constrain tension. then study corresponding Bose–Einstein condensate (BEC) gravitational system and determine critical stability region BEC stellar...
We consider a generalized uncertainty principle (GUP) corresponding to deformation of the fundamental commutator obtained by adding term quadratic in momentum. From this GUP, we compute corrections Unruh effect and related temperature, first following heuristic derivation, then more standard field theoretic calculation. In limit small deformations, recover thermal character radiation. Corrections temperature at order deforming parameter are compared for two approaches, found be agreement as...
We employ the minimal geometric deformation approach to gravitational decoupling (MGD- decoupling) in order build an exact anisotropic version of Schwarzschild interior solution a space-time with cosmological constant. Contrary well-known interior, matter density new is not uniform and possesses subluminal sound speed. It therefore satisfies all standard physical requirements for candidate astrophysical object.
We consider a solution of the effective four-dimensional brane-world equations, obtained from general relativistic Schwarzschild metric via principle minimal geometric deformation, and investigate corresponding signatures stemming possible existence warped extra-dimension. In particular, we derive bounds on an extra-dimensional parameter, closely related with fundamental gravitational length, experimental results classical tests relativity in Solar system.
We study stars in the brane-world by employing principle of minimal geometric deformation and find that black hole metrics with a tidal charge are consistently recovered suitable limit. This procedure allows us to determine as function ADM mass (and brane tension). A minimum for semiclassical microscopic holes can then be derived, relevant impact description events at LHC.
The Generalized Uncertainty Principle (GUP) has been directly applied to the motion of (macroscopic) test bodies on a given space-time in order compute corrections classical orbits predicted Newtonian Mechanics or General Relativity. These generically violate Equivalence Principle. GUP also indirectly gravitational source by relating modified Hawking temperature deformation background metric. Such deformed metric determines new geodesic motions without violating We point out here that two...
We investigate how a spherically symmetric scalar field can modify the Schwarzschild vacuum solution when there is no exchange of energy-momentum between and central source metric.This system described by means gravitational decoupling Minimal Geometric Deformation (MGD-decoupling), which allows us to show that, under MGD paradigm, modified in such way that naked singularity appears.
We consider black holes generically sourced by quantum matter described regular wavefunctions. This allows for integrable effective energy densities and the removal of Cauchy horizons in spherically symmetric configurations. Moreover, we identify ultrarigid rotation Kerr spacetime as causing existence an inner horizon rotating systems, describe general properties cores at centre with singularities no horizon.
Static and stationary regular black holes are examined under a minimal set of requirements consisting (i) the existence well defined event horizon (ii) weak energy condition for matter sourcing geometry. We perform our analysis by means gravitational decoupling approach find hairy solutions free curvature singularities. identify source producing deformation Minkowski vacuum such that maximum is Schwarzschild solution static case, Kerr metric case.
We consider uncertainty principles which take into account the role of gravity and possible existence extra spatial dimensions. Explicit expressions for such generalized in 4 + n dimensions are given their holographic properties investigated. In particular, we show that predicted number degrees freedom enclosed a volume matches counting only one available generalizations without
We reconsider perturbative unitarity violation in the standard model Higgs inflation model. show that Cutkosky cutting rule implied by is fulfilled at one-loop. This a strong indication restored order perturbation theory. then resum certain one-loop diagrams and relevant dressed amplitude fulfills exactly. an example of self-healing mechanism. The original thus consistent does not require any new physics beyond least up to Planck scale.
We consider the effects of gravitons in collapse baryonic matter that forms a black hole. first note effective number (soft off-shell) account for (negative) Newtonian potential energy generated by baryons is conserved and always agreement with Bekenstein's area law holes. Moreover, their (positive) interaction reproduces expected post-Newtonian correction becomes order total ADM mass system when size collapsing object approaches its gravitational radius. This result supports scenario which...
We derive the Hawking spectrum of fermions emitted by a minimally geometric deformed (MGD) black hole. The MGD naturally describes quantum effects on geometry in form length scale related, for instance, to existence extra dimensions. dynamics is described context generalised uncertainty principle and likewise contains associated with nature space-time. then show that emission practically indistinguishable from thermal large hole masses, but total flux can vanish small finite mass. This...