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Author Guerrero, M.; Olmo, G.J.; Rubiera-Garcia, D.
Title Double shadows of reflection-asymmetric wormholes supported by positive energy thin-shells Type Journal Article
Year 2021 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 066 - 26pp
Keywords (up) modified gravity; Wormholes; gravity
Abstract We consider reflection-asymmetric thin-shell wormholes within Palatini f(R) gravity using a matching procedure of two patches of electrovacuum space-times at a hypersurface (the shell) via suitable junction conditions. The conditions for having (linearly) stable wormholes supported by positive-energy matter sources are determined. We also identify some subsets of parameters able to locate the shell radius above the event horizon (when present) but below the photon sphere (on both sides). We illustrate with an specific example that such two photon spheres allow an observer on one of the sides of the wormhole to see another (circular) shadow in addition to the one generated by its own photon sphere, which is due to the photons passing above the maximum of the effective potential on its side and bouncing back across the throat due to a higher effective potential on the other side. We finally comment on the capability of these double shadows to seek for traces of new gravitational physics beyond that described by General Relativity.
Address [Guerrero, Merce; Rubiera-Garcia, Diego] Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain, Email: merguerr@ucm.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000644501000029 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4823
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Author Olmo, G.J.; Rubiera-Garcia, D.
Title Semiclassical geons at particle accelerators Type Journal Article
Year 2014 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 02 Issue 2 Pages 010 - 25pp
Keywords (up) modified gravity; Wormholes; quantum black holes
Abstract We point out that in certain four-dimensional extensions of general relativity constructed within the Palatini formalism stable self-gravitating objects with a discrete mass and charge spectrum may exist. The incorporation of nonlinearities in the electromagnetic field may effectively reduce their mass spectrum by many orders of magnitude. As a consequence, these objects could be within (or near) the reach of current particle accelerators. We provide an exactly solvable model to support this idea.
Address [Omla, Gonzalo J.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000332711400010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1733
Permanent link to this record
 

 
Author Wang, D.
Title Model-independent traversable wormholes from baryon acoustic oscillations Type Journal Article
Year 2023 Publication Physics of the Dark Universe Abbreviated Journal Phys. Dark Universe
Volume 42 Issue Pages 101306 - 8pp
Keywords (up) Traversable wormholes; Dark energy; Baryon acoustic oscillations
Abstract In this paper, we investigate the model-independent traversable wormholes from baryon acoustic oscillations. Firstly, we place the statistical constraints on the average dark energy equation of state Wav by only using BAO data. Subsequently, two specific wormhole solutions are obtained, i.e, the cases of the constant redshift function and a special choice for the shape function. For the first case, we analyze the traversabilities of the wormhole configuration, and for the second case, we find that one can construct theoretically a traversable wormhole with infinitesimal amounts of average null energy condition violating phantom fluid. Furthermore, we perform the stability analysis for the first case, and find that the stable equilibrium configurations may increase for increasing values of the throat radius of the wormhole in the cases of a positive and a negative surface energy density. It is worth noting that the obtained wormhole solutions are static and spherically symmetrical metric, and that we assume Wav to be a constant between different redshifts when placing constraints, hence, these wormhole solutions can be interpreted as stable and static phantom wormholes configurations at some certain redshift which lies in the range [0.32, 2.34].
Address [Wang, Deng] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46980 Paterna, Spain, Email: cstar@nao.cas.cn
Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:001122744700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5853
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Author Santos, A.C.L.; Muniz, C.R.; Maluf, R.V.
Title Yang-Mills Casimir wormholes in D=2+1 Type Journal Article
Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 09 Issue 9 Pages 022 - 24pp
Keywords (up) Wormholes; Exact solutions; black holes and black hole thermodynamics in GR and beyond; gravity
Abstract This work presents new three-dimensional traversable wormhole solutions sourced by the Casimir density and pressures related to the quantum vacuum fluctuations in Yang-Mills (Y-M) theory. We begin by analyzing the noninteracting Y-M Casimir wormholes, initially considering an arbitrary state parameter omega and determine a simple constant wormhole shape function. Next, we introduce a new methodology for deforming the state parameter to find well-behaved redshift functions. The wormhole can be interpreted as a legitimate Casimir wormhole with an expected average state parameter of omega = 2. Then, we investigate the wormhole curvature properties, energy conditions, and stability. Furthermore, we discover a novel family of traversable wormhole solutions sourced by the quantum vacuum fluctuations of interacting Yang-Mills fields with a more complex shape function. Deforming the effective state parameter similarly, we obtain well-behaved redshift functions and traversable wormhole solutions. Finally, we examine the energy conditions and stability of solutions in the interacting scenario and compare to the noninteracting case.
Address [Santos, Alana C. L.; Maluf, Roberto V.] Univ Fed Ceara UFC, Departamento Fis, Campus Pici,6030, BR-60455760 Fortaleza, Ceara, Brazil, Email: alanasantos@fisica.ufc.br;
Corporate Author Thesis
Publisher IOP Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:001196198800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6031
Permanent link to this record