| Records |
| Author |
Araujo Filho, A.A.; Furtado, J.; Reis, J.A.A.S.; Silva, J.E.G. |
| Title |
Thermodynamical properties of an ideal gas in a traversable wormhole |
Type |
Journal Article |
| Year |
2023 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
| Volume |
40 |
Issue |
24 |
Pages |
245001 - 20pp |
| Keywords |
wormhole; thermodynamic properties; Ellis wormhole |
| Abstract |
In this work, we analyze the thermodynamic properties of non-interacting particles under influence of the gravitational field of a traversable wormhole. In particular, we investigate how the thermodynamic quantities are affected by the Ellis wormhole geometry, considering three different regions to our study: asymptotically far, close to the throat, and at the throat. The thermodynamic quantities turn out to depend strongly on parameter that controls the wormhole throat radius. By varying it, there exist an expressive modification in the thermodynamic state quantities, exhibiting both usual matter and dark energy-like behaviors. Finally, the interactions are regarded to the energy density and it seems to indicate that it “cures” the dark energy-like features. |
| Address |
[Araujo Filho, A. A.] Univ Valencia, Dept Fis Teor, Burjassot 46100, Valencia, Spain, Email: dilto@fisica.ufc.br |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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ISSN  |
0264-9381 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:001098744300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5792 |
| Permanent link to this record |
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| Author |
Araujo Filho, A.A. |
| Title |
Analysis of a regular black hole in Verlinde's gravity |
Type |
Journal Article |
| Year |
2024 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
| Volume |
41 |
Issue |
1 |
Pages |
015003 - 30pp |
| Keywords |
Verlinde's emergent gravity; dark matter; shadows; black hole |
| Abstract |
This work focuses on the examination of a regular black hole within Verlinde's emergent gravity, specifically investigating the Hayward-like (modified) solution. The study reveals the existence of three horizons under certain conditions, i.e. an event horizon and two Cauchy horizons. Our results indicate regions which phase transitions occur based on the analysis of heat capacity and Hawking temperature. To compute the latter quantity, we utilize three distinct methods: the surface gravity approach, Hawking radiation, and the application of the first law of thermodynamics. In the case of the latter approach, it is imperative to introduce a correction to ensure the preservation of the Bekenstein-Hawking area law. Geodesic trajectories and critical orbits (photon spheres) are calculated, highlighting the presence of three light rings. Additionally, we investigate the black hole shadows. Furthermore, the quasinormal modes are explored using third- and sixth-order Wentzel-Kramers-Brillouin approximations. In particular, we observe stable and unstable oscillations for certain frequencies. Finally, in order to comprehend the phenomena of time-dependent scattering in this scenario, we provide an investigation of the time-domain solution. |
| Address |
[Araujo Filho, A. A.] Univ Valencia, Ctr Mixto Univ Valencia, CSIC, Dept Fis Teor, Burjassot 46100, Valencia, Spain, Email: dilto@fisica.ufc.br |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0264-9381 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:001114102700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5841 |
| Permanent link to this record |
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| Author |
Araujo Filho, A.A.; Hassanabadi, H.; Heidari, N.; Kriz, J.; Zare, S. |
| Title |
Gravitational traces of bumblebee gravity in metric-affine formalism |
Type |
Journal Article |
| Year |
2024 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
| Volume |
41 |
Issue |
5 |
Pages |
055003 - 21pp |
| Keywords |
bumblebee gravity; metric affine formalism; shadows |
| Abstract |
This work explores various manifestations of bumblebee gravity within the metric-affine formalism. We investigate the impact of the Lorentz violation parameter, denoted as X, on the modification of the Hawking temperature. Our calculations reveal that as X increases, the values of the Hawking temperature attenuate. To examine the behavior of massless scalar perturbations, specifically the quasinormal modes, we employ the Wentzel-Kramers-Brillouin method. The transmission and reflection coefficients are determined through our calculations. The outcomes indicate that a stronger Lorentz-violating parameter results in slower damping oscillations of gravitational waves. To comprehend the influence of the quasinormal spectrum on time-dependent scattering phenomena, we present a detailed analysis of scalar perturbations in the time-domain solution. Additionally, we conduct an investigation on shadows, revealing that larger values of X correspond to larger shadow radii. Furthermore, we constrain the magnitude of the shadow radii using the EHT horizon-scale image of SgrA* . Finally, we calculate both the time delay and the deflection angle. |
| Address |
[Araujo Filho, A. A.] Univ Valencia, CSIC, Dept Fis Teor, Ctr MIxto Univ Valencia, Burjassot 46100, Valencia, Spain, Email: dilto@fisica.ufc.br |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0264-9381 |
ISBN |
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Medium |
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| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:001152994800001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5925 |
| Permanent link to this record |
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| Author |
Navarro-Salas, J. |
| Title |
Black holes, conformal symmetry, and fundamental fields |
Type |
Journal Article |
| Year |
2024 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
| Volume |
41 |
Issue |
8 |
Pages |
085003 - 14pp |
| Keywords |
black holes; horizons; singularities; conformal symmetry; quantum fields; Standard Model |
| Abstract |
Cosmic censorship protects the outside world from black hole singularities and paves the way for assigning entropy to gravity at the event horizons. We point out a tension between cosmic censorship and the quantum backreacted geometry of Schwarzschild black holes, induced by vacuum polarization and driven by the conformal anomaly. A similar tension appears for the Weyl curvature hypothesis at the Big Bang singularity. We argue that the requirement of exact conformal symmetry resolves both conflicts and has major implications for constraining the set of fundamental constituents of the Standard Model. |
| Address |
[Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, IFIC, CSIC, E-46100 Burjassot, Valencia, Spain, Email: jnavarro@ific.uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0264-9381 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:001187435100001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
6029 |
| Permanent link to this record |
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| Author |
Botella-Soler, V.; Glendinning, P. |
| Title |
Emergence of hierarchical networks and polysynchronous behaviour in simple adaptive systems |
Type |
Journal Article |
| Year |
2012 |
Publication |
Europhysics Letters |
Abbreviated Journal |
EPL |
| Volume |
97 |
Issue |
5 |
Pages |
50004 - 5pp |
| Keywords |
|
| Abstract |
We describe the dynamics of a simple adaptive network. The network architecture evolves to a number of disconnected components on which the dynamics is characterized by the possibility of differently synchronized nodes within the same network (polysynchronous states). These systems may have implications for the evolutionary emergence of polysynchrony and hierarchical networks in physical or biological systems modeled by adaptive networks. |
| Address |
[Botella-Soler, V.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: vicente.botella@uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Epl Association, European Physical Society |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0295-5075 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000301952600004 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
958 |
| Permanent link to this record |
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| Author |
Motohashi, H.; Starobinsky, A.A. |
| Title |
Constant-roll inflation: Confrontation with recent observational data |
Type |
Journal Article |
| Year |
2017 |
Publication |
Europhysics Letters |
Abbreviated Journal |
EPL |
| Volume |
117 |
Issue |
3 |
Pages |
39001 - 3pp |
| Keywords |
|
| Abstract |
The previously proposed class of phenomenological inflationary models in which the assumption of inflaton slow-roll is replaced by the more general, constant-roll condition is compared with the most recent cosmological observational data, mainly the Planck ones. Models in this two-parametric class which remain viable appear to be close to the slow-roll ones, and their inflaton potentials are close to (but still different from) that of the natural inflation model. The permitted regions for the two model parameters are presented. |
| Address |
[Motohashi, Hayato] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46980 Valencia, Spain |
| Corporate Author |
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Thesis |
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| Publisher |
Epl Association, European Physical Society |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0295-5075 |
ISBN |
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Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000401165300001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3134 |
| Permanent link to this record |
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| Author |
Bueno Rogerio, R.J.; Lima, R.D.; Duarte, L.; Hoff da Silva, J.M.; Dias, M.; Senise, C.R. |
| Title |
Mass-dimension-one fermions and their gravitational interaction |
Type |
Journal Article |
| Year |
2019 |
Publication |
Europhysics Letters |
Abbreviated Journal |
EPL |
| Volume |
128 |
Issue |
2 |
Pages |
20004 - 6pp |
| Keywords |
|
| Abstract |
We investigate in detail the interaction between the spin-(1/2) field endowed with mass dimension one and the graviton. We obtain an interaction vertex that combines the characteristics of scalar-graviton and Dirac's fermion-graviton vertices, due to the scalar-dynamic attribute and the fermionic structure of the mass-dimension-one field. It is shown that this vertex obeys the Ward-Takahashi identity, ensuring the gauge invariance for the interaction. In the contribution of the mass-dimension-one fermion to the graviton propagator at one-loop level, we found the conditions for the cancellation of the tadpole term by a cosmological counterterm. We calculate the scattering process for arbitrary momentum. For low energies, the result reveals that only the scalar sector present in the vertex contributes to the gravitational potential. Finally, we evaluate the non-relativistic limit of the gravitational interaction and obtain an attractive Newtonian potential, as required for a dark-matter candidate. |
| Address |
[Bueno Rogerio, R. J.] Univ Fed Itajuba UNIFEI, IFQ, Ave BPS 1303, BR-37500903 Itajuba, MG, Brazil |
| Corporate Author |
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Thesis |
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| Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0295-5075 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000518763000003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4317 |
| Permanent link to this record |
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| Author |
Beltran Jimenez, J.; Heisenberg, L.; Olmo, G.J.; Rubiera-Garcia, D. |
| Title |
Born-Infeld inspired modifications of gravity |
Type |
Journal Article |
| Year |
2018 |
Publication |
Physics Reports |
Abbreviated Journal |
Phys. Rep. |
| Volume |
727 |
Issue |
|
Pages |
1-129 |
| Keywords |
Born-Infeld gravity; Astrophysics; Black holes; Cosmology; Early universe; Compact objects; Singularities |
| Abstract |
General Relativity has shown an outstanding observational success in the scales where it has been directly tested. However, modifications have been intensively explored in the regimes where it seems either incomplete or signals its own limit of validity. In particular, the breakdown of unitarity near the Planck scale strongly suggests that General Relativity needs to be modified at high energies and quantum gravity effects are expected to be important. This is related to the existence of spacetime singularities when the solutions of General Relativity are extrapolated to regimes where curvatures are large. In this sense, Born-Infeld inspired modifications of gravity have shown an extraordinary ability to regularise the gravitational dynamics, leading to non-singular cosmologies and regular black hole spacetimes in a very robust manner and without resorting to quantum gravity effects. This has boosted the interest in these theories in applications to stellar structure, compact objects, inflationary scenarios, cosmological singularities, and black hole and wormhole physics, among others. We review the motivations, various formulations, and main results achieved within these theories, including their observational viability, and provide an overview of current open problems and future research opportunities. |
| Address |
[Beltran Jimenez, Jose] Univ Autonoma Madrid, CSIC, Inst Fis Teor, E-28049 Madrid, Spain, Email: jose.beltran@uam.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-1573 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
WOS:000425482900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3497 |
| Permanent link to this record |
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| Author |
Olmo, G.J.; Rubiera-Garcia, D.; Wojnar, A. |
| Title |
Stellar structure models in modified theories of gravity: Lessons and challenges |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physics Reports |
Abbreviated Journal |
Phys. Rep. |
| Volume |
876 |
Issue |
|
Pages |
1-75 |
| Keywords |
Stellar structure; Modified gravity; Palatini formalism; Neutron stars; Brown dwarfs; Relativistic stars; Weak field; f(R) theories; Born-Infeld theory; Horndeski theory |
| Abstract |
The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong field regime of General Relativity, and opens fruitful avenues for the exploration of new gravitational physics. The latter can be captured via modified theories of gravity, which modify the Einstein-Hilbert action of General Relativity and/or some of its principles. These theories typically change the Tolman-Oppenheimer-Volkoff equations of stellar's hydrostatic equilibrium, thus having a large impact on the astrophysical properties of the corresponding stars and opening a new window to constrain these theories with present and future observations of different types of stars. For relativistic stars, such as neutron stars, the uncertainty on the equation of state of matter at supranuclear densities intertwines with the new parameters coming from the modified gravity side, providing a whole new phenomenology for the typical predictions of stellar structure models, such as mass-radius relations, maximum masses, or moment of inertia. For non-relativistic stars, such as white, brown and red dwarfs, the weakening/strengthening of the gravitational force inside astrophysical bodies via the modified Newtonian (Poisson) equation may induce changes on the star's mass, radius, central density or luminosity, having an impact, for instance, in the Chandrasekhar's limit for white dwarfs, or in the minimum mass for stable hydrogen burning in high-mass brown dwarfs. This work aims to provide a broad overview of the main such results achieved in the recent literature for many such modified theories of gravity, by combining the results and constraints obtained from the analysis of relativistic and non-relativistic stars in different scenarios. Moreover, we will build a bridge between the efforts of the community working on different theories, formulations, types of stars, theoretical modelings, and observational aspects, highlighting some of the most promising opportunities in the field. |
| Address |
[Olmo, Gonzalo J.] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC, Valencia 46100, Spain, Email: gonzalo.olmo@uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-1573 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000570298900001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4531 |
| Permanent link to this record |
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| Author |
Del Debbio, L.; Ramos, A. |
| Title |
Lattice determinations of the strong coupling |
Type |
Journal Article |
| Year |
2021 |
Publication |
Physics Reports |
Abbreviated Journal |
Phys. Rep.-Rev. Sec. Phys. Lett. |
| Volume |
920 |
Issue |
|
Pages |
1-71 |
| Keywords |
QCD; Renormalization; Strong coupling; Lattice field theory |
| Abstract |
Lattice QCD has reached a mature status. State of the art lattice computations include u, d, s (and even the c) sea quark effects, together with an estimate of electromagnetic and isospin breaking corrections for hadronic observables. This precise and first principles description of the standard model at low energies allows the determination of multiple quantities that are essential inputs for phenomenology and not accessible to perturbation theory. One of the fundamental parameters that are determined from simulations of lattice QCD is the strong coupling constant, which plays a central role in the quest for precision at the LHC. Lattice calculations currently provide its best determinations, and will play a central role in future phenomenological studies. For this reason we believe that it is timely to provide a pedagogical introduction to the lattice determinations of the strong coupling. Rather than analysing individual studies, the emphasis will be on the methodologies and the systematic errors that arise in these determinations. We hope that these notes will help lattice practitioners, and QCD phenomenologists at large, by providing a self-contained introduction to the methodology and the possible sources of systematic error. The limiting factors in the determination of the strong coupling turn out to be different from the ones that limit other lattice precision observables. We hope to collect enough information here to allow the reader to appreciate the challenges that arise in order to improve further our knowledge of a quantity that is crucial for LHC phenomenology. Crown Copyright & nbsp;(c) 2021 Published by Elsevier B.V. All rights reserved. |
| Address |
[Del Debbio, Luigi] Univ Edinburgh, Sch Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland, Email: luigi.del.debbio@ed.ac.uk; |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0370-1573 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
|
| Notes |
WOS:000659901700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4843 |
| Permanent link to this record |
