4th Valencia Winter Workshop on Theoretical Physics

Contribution List

17. Opening

14/12/2020, 09:45

2. Luis C.B. Crispino (UFPA,Brazil)

14/12/2020, 10:15

The first attempts to measure light deflection by the Sun.

1. Adrià Delhom(UV, Valencia)

14/12/2020, 11:20

title: Inconsistencies in four-dimensional Einstein-Gauss-Bonnet gravity

abstract:We will outline several inconsistencies about the recently proposed four-dimensional Einstein-Gauss-Bonnet theory.

3. Mercè Guerrero (UCM, Madrid)

14/12/2020, 12:00

Double shadows of asymmetric wormhole in Palatini f(R)

Abstract: We discuss the stability and appearance of an asymmetric thin shell wormhole within the Palatini
f(R) gravity matching two Reissner-Nordström space-times with different masses and charges via
suitable junction conditions.

35. Fabrizio Di Giovanni (UV, Valencia)

14/12/2020, 12:40

On the dynamical bar-mode instability of spinning bosonic stars

Abstract:We report results from three-dimensional numerical-relativity simulations of spinning bosonic stars, both considering a scalar field or a vector (Proca) field. In both cases, the bosonic field is assumed complex and massive. The scalar star is always affected by the growth of a non-axisymmetric instability which triggers...

4. Silvia Pla García (UV, Valencia)

14/12/2020, 15:00

Particle creation by electric and gravitational fields

5. Llorenç Espinosa Portalés (IFT, Madrid)

14/12/2020, 15:40

Long range enhanced mutual information from inflation

6. Robert Santacruz Zaragoza (U. New Brunswick, Canada)

14/12/2020, 16:20

Black Hole collapse and bounce in effective loop quantum gravity

7. Iarley P. Lobo (UFLA/UFPB,Brasil)

14/12/2020, 17:00

Reaching Planck scale sensitivity with muon lifetimes from Finsler measures.

Abstract: Planck scale modified dispersion relations are one way how to capture the influence of quantum gravity on the propagation of fundamental point particles effectively. We derive the time dilation between an observer's or particle's proper time, given by a Finslerian length measure induced from a modified...

8. Carolina Benone (UFPA, Brasil)

14/12/2020, 17:55

22. Adrian Del Río (IST, Lisboa)

15/12/2020, 10:00

Gravitational-wave signatures of quantum gravity.

Abstract: We show that gravitational-wave astronomy has the potential to inform us on quantum aspects of black holes. Based on Bekenstein's quantization, we find that black hole area discretization could impart observable imprints to the gravitational-wave signal from a pair of merging black holes, affecting their absorption properties during...

10. Adrián Casado Turrión (UCM, Madrid)

15/12/2020, 10:50

Accelerating towards an ambidextrous world: chiral symmetry restoration by the Unruh effect

Abstract:In this presentation we shall consider the possibility of triggering the chiral phase transition of QCD through uniform acceleration, i.e. by the Unruh effect. Using Chiral Perturbation Theory at leading order and in the large N limit (with N being the number of pions) as the effective...

11. Sérgio Vinicius Monteiro Castelo Branco Xavier

15/12/2020, 11:30

Shadows of charged rotating black holes: Kerr-Newman versus Kerr-Sen

12. Matheus A. Marquez (UFPB,Brasil)

15/12/2020, 12:05

New results on magnetic monopoles.

38. Adrià Delhom (UV)

15/12/2020, 12:55

title: Ghosts in metric-affine higher order curvature gravity

abstract: We disprove the widespread belief that higher order curvature theories of gravity in the metric-affine formalism are generally ghost-free. This is clarified by considering a sub-class of theories constructed only with the Ricci tensor and showing that the non-projectively invariant sector propagates ghost-like degrees of...

13. Francisco S.N. Lobo

15/12/2020, 15:00

Thin-shell and and black-bounce traversable wormholes.

14. Alfredo Delgado Miravet (UCM, Madrid)

15/12/2020, 16:05

The imprint of ultralight vector fields on gravitational wave propagation.

Abstract: We study the effects of ultralight vector field (ULVF) dark matter on gravitational wave propagation. We find that the coherent oscillations of the vector field suppress the amplitude of gravity waves as compared to the $\Lambda$CDM prediction. The effect is enhanced for smaller vector field masses and...

15. Diego Rubiera-Garcia (UCM, Madrid)

15/12/2020, 17:00

Testing modified gravity with relativistic and non-relativistic stars.

Abstract: I will discuss the most promising opportunities for testing modified gravity effects using models of stellar structure for both relativistic (neutron stars) and non-relativistic (brown, red, white) stars.

16. Caio F.B. Macedo (UFPA,Brasil)

15/12/2020, 18:00

9. João Luis Rosa (U. Tartu, Estonia)

16/12/2020, 10:00

Existence and stability of relativistic fluid spheres supported by thin-shells.

18. Avishek Dusoye (UCT, Cape Town)

16/12/2020, 10:50

Disformal couplings in a CDM background cosmology.

Abstract: The coupled quintessence model with disformal couplings is treated here to mimic the LCDM background. Using this approach, the quintessence potential does not have to be specified. The model considers a generic fluid coupled to the quintessence, which is specified to be either dark matter or a relativistic fluid. The LCDM background...

20. Marco Aurélio Abreu de Paula

16/12/2020, 11:30

Electrically charged black holes in linear and nonlinear electrodynamics: Geodesic analysis and scalar absorption.

19. Francisco José Maldonado Torralba (UCT and U.Groningen)

16/12/2020, 12:10

21. Renan Batalha Magalhaes

16/12/2020, 15:05

Persistence of wormholes in Palatini gravity

23. Haroldo Cilas Duarte Lima Junior

16/12/2020, 15:40

4D Einstein-Gauss-Bonnet gravity: Massless particles and absorption of planar spin-0 waves.

24. Gerardo Mora

16/12/2020, 16:20

25. Sergi Navarro-Albalat (University of Texas)

16/12/2020, 17:00

Modelling extreme mass ratio inspirals

26. João Paulo Bessa Brito

16/12/2020, 17:40

Synchrotron geodesic radiation in Schwarzschild-de Sitter spacetime.

36. Andreu Masó (UV, València)

16/12/2020, 18:20

Boson Stars in Palatini f(R) gravity

27. Aneta Wojnar (U. Tartu, Estonia)

17/12/2020, 10:00

Title: Low-mass stars in modified gravity

Abstract:

I will present modified gravity impacts on stars' early evolution, such as Hayashi tracks and radiative core development, together with the measured quantities such as effective temperature, masses, luminosities, and abundance of light elements. The last one introduces an additional uncertainty to age determination techniques of young...

28. Sergi Nadal (UV)

17/12/2020, 10:50

Title: Renormalization, running couplings, and decoupling for the Yukawa model in curved spacetime

29. Simon Boudet (University of Trento, Italy)

17/12/2020, 11:30

"Super-entropic black hole with Immirzi hair"

Abstract: "In the context of f(R) generalizations to the Holst action, endowed with a dynamical Immirzi field, we derive an analytic solution describing asymptotically Anti-de Sitter black holes with hyperbolic horizon. These exhibit a scalar hair of the second kind, which ultimately depends on the Immirzi field radial behaviour. In particular,...

30. Rafael Bernar (UFPA, Brasil)

17/12/2020, 12:05

Quantum superradiance of a charged scalar field in Reissner-Nordström
spacetime.

Abstract: We analyze the quantum version of charge superradiance for a massless scalar field in Reissner-Nordström spacetime. We compute the expectation
values of the operators associated to the fluxes of charge and energy
from the black hole in the vacuum state which has no particles as past
null infinity....

37. Albert Petrov (UFPB, João Pessoa)

17/12/2020, 13:00

Metric-affine bumblebee gravity: quantum aspects, based on https://arxiv.org/abs/2010.06391

31. Juan Margalef (UC3M/PennState)

17/12/2020, 15:00

The geometric formulation of the covariant Phase Space with boundaries.

Abstract: In this talk, I will introduce the relative bicomplex framework, a new formalism which is the natural one to deal with the covariant phase space of theories with boundaries. I will show that it provides a formal equivalence between the relative version of a theory with boundary and the non-relative version of...

32. Flavio Bombacigno (UV, Valencia)

17/12/2020, 15:50

Gravitational Landau damping for massive scalar modes.

Abstract: We establish the possibility of Landau damping for gravitational scalar waves which propagate in a non-collisional gas of particles. In particular, under the hypothesis of homogeneity and isotropy, we describe the medium at the equilibrium with a J\"uttner-Maxwell distribution, and we analytically determine the damping rate from...

33. Param Singh (LSU, USA)

17/12/2020, 16:45

Starting low energy scale inflation in closed universes.Title: Onset of Starobinsky inflation in spatially closed FLRW model

Abstract: Recent CMB data favors a spatially closed FLRW model and low energy inflation such as sourced by the Starobinsky potential. An age old problem with the latter models is that they result in a recollapse of the universe and a big crunch singularity before...

34. J. Fernando Barbero G. (IEM, Madrid)

17/12/2020, 17:50

A concise symplectic formulation for tetrad gravity.

Abstract: I will discuss a simple symplectic formulation for tetrad gravity that leads to the real Ashtekar variables in a direct and
transparent way. It also sheds light on the role of the Immirzi
parameter and the time gauge.