2nd Valencia Winter Workshop on Theoretical Physics
from
Tuesday, 11 December 2018 (10:00)
to
Friday, 14 December 2018 (17:00)
Monday, 10 December 2018
Tuesday, 11 December 2018
10:30
Global monopoles in Palatini gravity

Gonzalo J. Olmo
(
UVIFIC
)
Global monopoles in Palatini gravity
Gonzalo J. Olmo
(
UVIFIC
)
10:30  11:30
Room: 444426  Seminari Física Teòrica
I'll present some recent results and new ideas on the effects that global monopoles combined with modified gravity à la Palatini could have for black holes and Hawking radiation.
11:30
TBA

Victor I. Afonso
(
UFCG (Brazil)
)
TBA
Victor I. Afonso
(
UFCG (Brazil)
)
11:30  12:30
Room: 444426  Seminari Física Teòrica
12:30
Inflation beyond GR

Héctor Ramírez
(
IFIC
)
Inflation beyond GR
Héctor Ramírez
(
IFIC
)
12:30  13:30
Room: 444426  Seminari Física Teòrica
Scalartensor theories of gravity have become a very rich framework from which one can construct viable phenomenological models of early and latetime cosmology. In particular for inflation, previous models constructed using the Horndeski Lagrangian give predictions which are now in tension with CMB data. On the other hand, by trying to fit the observations, one would find instabilities at the level of the quantum perturbations. Furthermore, computing the standard inflationary observables in a semianalytical way is a nontrivial task. In this talk, first I will introduce a novel scalarvectortensor framework (SVT) from which Horndeski is a subclass theory. I will show a simple inflationary model using the SVT Lagrangian and, then, using the standard Ginflation parametrization, a new mechanism to avoid instabilities with a phenomenological model which fits CMB predictions, this by computing observables using the Generalized and Optimized SlowRoll techniques.
15:00
Generalized Geometry and supersymmetric Sigmamodels

Javier Orts Romero
(
IFICUV
)
Generalized Geometry and supersymmetric Sigmamodels
Javier Orts Romero
(
IFICUV
)
15:00  16:00
Room: 444426  Seminari Física Teòrica
Generalized Complex Geometry was introduced by the British mathematician Nigel Hitchin and further developed by his PhD students Gil Cavalcanti and specially Marco Gualtieri. The aim of Generalized Geometry is to combine symplectic and complex geometries in a single structure. In this talk, I will introduce the basic concepts for this theory and how it arises in a natural way in supersymmetric nonlinear Sigmamodels.
16:00
Conformal and projective superspaces in N=2 supersymmetry

Adriana Guerrero Menkara
(
IFICUV
)
Conformal and projective superspaces in N=2 supersymmetry
Adriana Guerrero Menkara
(
IFICUV
)
16:00  17:00
Room: 444426  Seminari Física Teòrica
Wednesday, 12 December 2018
10:30
TBA

Cecilia Bejarano
(
IAFE  U. Buenos Aires (Argentina)
)
TBA
Cecilia Bejarano
(
IAFE  U. Buenos Aires (Argentina)
)
10:30  11:30
Room: 444426  Seminari Física Teòrica
11:30
Electromagnetism induced by projective symmetry in metricaffine gravity

Alejandro Jiménez Cano
(
U. Granada
)
Electromagnetism induced by projective symmetry in metricaffine gravity
Alejandro Jiménez Cano
(
U. Granada
)
11:30  12:30
Room: 444426  Seminari Física Teòrica
TBA
12:30
Nice, clean and easy: how spacetime singularities can be resolved within Palatini gravity.

Diego RubieraGarcia
(
Instituto de Astrofísica, Lisboa
)
Nice, clean and easy: how spacetime singularities can be resolved within Palatini gravity.
Diego RubieraGarcia
(
Instituto de Astrofísica, Lisboa
)
12:30  13:30
Room: 444426  Seminari Física Teòrica
We review the trouble with spacetime singularities within General Relativity and how gravitational theories formulated in metricaffine spaces and with a nice analogy with crystalline structures can have the key to their resolution. Focusing on spherically symmetric black holes by simplicity, we shall see the simple economy of these models in getting rid of such singularities. Some elements of the extension of this result to the axisymmetric scenario will also be discussed.
Thursday, 13 December 2018
10:30
Particle creation by wormholes

Gonzalo Gurrea
(
UPV (Valencia)
)
Particle creation by wormholes
Gonzalo Gurrea
(
UPV (Valencia)
)
10:30  11:30
Room: 444426  Seminari Física Teòrica
Following the valuable technique of 2D moving mirror model, used to mimic Black Holes spacetime geometry, quantum modeling of a 1+1 wormhole and possible particle production is being analyzed. Application to viability of a time machine is also discussed.
11:30
Dynamical formation of Proca stars and quasistationary solitonic objects.

Fabrizio Di Giovanni
(
UV
)
Dynamical formation of Proca stars and quasistationary solitonic objects.
Fabrizio Di Giovanni
(
UV
)
11:30  12:30
Room: 444426  Seminari Física Teòrica
The dawn of gravitationalwave astronomy opens up an observational window to probe the true nature of astrophysical black hole candidates. These are widely believe to be well described, when near equilibrium, by the Kerr metric. But more exotic theoretical possibilities have been put forward, including horizonless compact objects. Such objects have the theoretical appeal of avoiding conceptual issues related to event horizons and spacetime singularities and could, in some circumstances, mimic the phenomenology of black holes. A notable example of these exotic compact objects are boson stars (BSs), which are selfgravitating, everywhere nonsingular, horizonless BoseEinstein condensates of massive scalar (scalar boson stars) or vector field (Proca stars). Two important questions can be raised about their dynamics. We may ask if they are stable, and more fundamentally if they may form dynamically. We perform fully nonlinear numerical simulations within the spherically symmetric Einstein(complex)Proca system. Starting with Proca field distributions that obey the Hamiltonian, momentum and Gaussian constraints, we show that the selfgravity of the system induces the formation of compact objects, known as Proca stars.
12:30
Magnetized accretion disks around Kerr black holes with scalar hair

Sergio GimenoSoler
(
UV
)
Magnetized accretion disks around Kerr black holes with scalar hair
Sergio GimenoSoler
(
UV
)
12:30  13:30
Room: 444426  Seminari Física Teòrica
Testing the true nature of black holes – the nohair hypothesis – will become increasingly more precise in the next few years as new observational data is collected in both the gravitational wave channel and the electromagnetic channel. In this talk we will consider numerically generated spacetimes of Kerr black holes with synchronised scalar hair and build stationary models of magnetized thick disks (or tori) around them. Our approach assumes that the disks are not selfgravitating, they obey a polytropic equation of state, the distribution of their specific angular momentum is constant, and they are marginally stable. Moreover, contrary to existing approaches in the literature, our models are thermodinamically relativistic, as the specific enthalpy of the fluid can adopt values significantly larger than unity. We study the dependence of the morphology and properties of the accretion tori on the type of black hole considered, from purely Kerr black holes with varying degrees of spin parameter. Comparisons between the disk properties for both types of black holes are presented. The sequences of magnetized, equilibrium disks models discussed in this study can be used as initial data for numerical relativity codes to investigate their dynamical (nonlinear) stability and used in tandem with raytracing codes to obtain synthetic images of black holes (i.e. shadows) in astrophysically relevant situations where the light source is provided by an emitting accretion disk.
15:00
TBA

Adrià DelhomLatorre
(
UVIFIC
)
TBA
Adrià DelhomLatorre
(
UVIFIC
)
15:00  16:00
Room: 444426  Seminari Física Teòrica
16:00
TBA

Gerardo Mora
(
UV
)
TBA
Gerardo Mora
(
UV
)
16:00  17:00
Room: 444426  Seminari Física Teòrica
Friday, 14 December 2018