Name: STARS2015 - 3rd Caribbean Symposium on Cosmology, Gravitation, Nuclear and Astroparticle Physics / SMFNS2015 - 4th International Symposium on Strong Electromagnetic Fields and Neutron Stars
Start: 2015-05-10T08:00:00-04:00
End: 2015-05-16T18:00:00-04:00
Location: No location set

STARS2015 - 3rd Caribbean Symposium on Cosmology, Gravitation, Nuclear and Astroparticle Physics / SMFNS2015 - 4th International Symposium on Strong Electromagnetic Fields and Neutron Stars

from Sunday 10 May 2015 (08:00) to Saturday 16 May 2015 (18:00)

Monday 4 May 2015
Tuesday 5 May 2015
Wednesday 6 May 2015
Thursday 7 May 2015
Friday 8 May 2015
Saturday 9 May 2015
Sunday 10 May 2015

08:30 Registration & Opening
Registration & Opening
08:30 - 09:00
09:00 Binary neutron stars from gravitational radiation to R-process nucleosynthesis - Tsvi Piran (The Hebrew University, Jerusalem, Israel)
Binary neutron stars from gravitational radiation to R-process nucleosynthesis (STARS2015)
- Tsvi Piran (The Hebrew University, Jerusalem, Israel)
09:00 - 09:40
Beyond being prime targets for gravitational radiation detection Compact Binary Mergers are the likely sources of short GRBs as well as the most likely origin of heavy R-process material. The latter ideas, a 25 years old proposition, has received observational support with the discovery of a Macro-nova - an IR signal that followed the short GRB 130603B and is the hallmark of newly formed R-process material. In this short review I describe the formation of the Macro-nova from matter ejected in the merger process and I discuss recent searches for a radio flare that should follow the Macro-nova signal (the Macro-nova and the associated radio flare are the analogues of a Supernova and a subsequent supernova remnant). Recent estimates of the cosmological evolution of rate of neutron star mergers (based on observations of short GRBs) lead to predictions on the cosmic evolution of abundance of heavy R-process material. I compare those with observations. Finally I discuss the implications of the observations of a Macro-nova and the predictions of Radio Flares for the identification of the exact positions of mergers whose Gravitational Radiation signals have been detected.
09:40 Black hole imaging as GR tests in the Galactic Center - Thomas Boller (M)
Black hole imaging as GR tests in the Galactic Center (STARS2015)
- Thomas Boller (M)
09:40 - 10:20
modified theory of gravitation, observational test, black hole imaging
10:20 Coffee break / Poster Session
Coffee break / Poster Session
10:20 - 10:40
10:40 A proposal of quantization with a minimal length present - Peter Hess
A proposal of quantization with a minimal length present (SMFNS2015)
- Peter Hess
10:40 - 11:20
The proposal consists of extending the 4-dimensional physical space to an 8-dimensional pseudo-complex (pc) space. The pc-extension introduces a minimal length as a parameter, thus, it is unaffected by Poincaré transformations. All continuous symmetries are maintained. In the extended space, standard quantization rules are applied and it is shown that after projection to the 4-dimensional physical space it is equivalent to non-commuting coordinates and non-commuting linear moments. A simple (1+1)-dimensional model is discussed investigating remnant effects of the 4-dimensional (in pc-coordinates) origin. The main result is: Extending to a higher dimensional space might offer to maintain the standard quantization rules and continuous symmetries, but at the same time simulating the effects of a minimal length and non-commutative properties of coordinates.
11:20 How to construct credible cosmic structures with exact solutions of General Relativity - Roberto SUSSMAN (ICN-UNAM, Mexico)
How to construct credible cosmic structures with exact solutions of General Relativity (STARS2015)
- Roberto SUSSMAN (ICN-UNAM, Mexico)
11:20 - 12:00
We provide specific examples of how a class of exact solutions of Einstein's equations (the Szekeres models) can be worked out to describe the evolution of a collection of over-densities and voids in assorted directions. The resulting structures can be used to study the full relativistic non-linear effects in the dynamics of structure formation and growth suppression, in gravitational lensing and in fitting observations in the galactic cluster and super-cluster scale.
12:00 Unification of Inflation and Dark Energy in a Non Singular Emergent Scenario - Eduardo Guendelman (Ben Gurion University)
Unification of Inflation and Dark Energy in a Non Singular Emergent Scenario (STARS2015)
- Eduardo Guendelman (Ben Gurion University)
12:00 - 12:30
A new class of gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold are studied in some detail. These models involve an additional R^2 (square of the scalar curvature) term as well as scalar matter field potentials of appropriate form so that the pertinent action is invariant under global Weyl-scale symmetry. Scale invariance is spontaneously broken upon integration of the equations of motion. After performing transition to the physical Einstein frame we obtain: (i) An effective potential for the scalar field with two flat regions which allows for a unified description of both early universe inflation as well as of present dark energy epoch; (ii) For a definite parameter range the model possesses a non-singular "emergent universe" solution which describes an initial phase of evolution that precedes the inflationary phase.
12:30 Lunch break
Lunch break
12:30 - 14:00
14:00 General relativity as a canonical gauge theory - Jürgen Struckmeier (GSI)
General relativity as a canonical gauge theory (STARS2015)
- Jürgen Struckmeier (GSI)
14:00 - 14:40
It is widely accepted that the fundamental laws of nature should follow from an action principle. This holds in particular for the laws determining the dynamics of the space-time geometry. The general principle of relativity requires the action principle to be maintained in its form under the transition from one reference frame to another, possibly non-inertial frame of reference. The particular subset of transformations of a system's dynamical variables that maintain the form of the action principle comprises the group of canonical transformations. By their construction, canonical transformations are defined by "generating functions". In this talk, a generating function will be presented that defines the given mapping of the connection coefficients ("Christoffel symbols"). In conjunction with the associated transformation rules for their canonical conjugates, this *unambiguously* yields a Hamiltonian that is form-invariant under a general transition to another reference frame. Thereby, a description of the dynamics of space-time is established that is not postulated but *derived from basic principles*, namely the action principle and the general principle of relativity. No further assumptions are incorporated. Neither a torsion of space-time is excluded *a priori*, nor a specific correlation of the Christoffel symbols with the metric is postulated. Moreover, the resulting theory satisfies the principle of scale invariance and is renormalizable. Remarkably, the corresponding Lagrangian of the presented formalism was already proposed in 1918 by A. Einstein in a personal letter to H. Weyl, reasoning analogies with other classical field theories.
14:40 Can General Relativity's N-body Lagrangian Be Obtained From Iterative Algebraic Scaling Equations? - Kenneth Nordtvedt (Montana State University)
Can General Relativity's N-body Lagrangian Be Obtained From Iterative Algebraic Scaling Equations? (STARS2015)
- Kenneth Nordtvedt (Montana State University)
14:40 - 15:20
A local system of bodies in General Relativity whose exterior metric field asymptotically approaches the Minkowski metric effaces any effects of the matter distribution exterior to the Minkowski boundary condition. A local gravitational system also exhibits certain invariances under time dilation and spatial contractions upon boosts. For composite body sources, interior effacement is manifest in General Relativity as well, leaving a single mass-energy parameter to represent the body in its spherical limit. By enforcing to all orders these properties of gravity which seem to hold in nature, a new method using linear algebraic scaling equations is developed which generates by an iterative process an N-body Lagrangian expansion for gravity which fulfills the mentioned properties --- exterior and interior effacement, and the time dilation and Lorentz contraction features of special relativity. The algebraic method is then used to produce the N-body gravity Lagrangian to the 1/c^4 order of expansion.
15:20 Stellar entropy and stellar evolution - Jorge Horvath (IAG-USP)
Stellar entropy and stellar evolution (STARS2015)
- Jorge Horvath (IAG-USP)
15:20 - 16:00
Evolution of entropy in stellar systems
16:00 Coffee break / Poster Session
Coffee break / Poster Session
16:00 - 16:20
16:20 Effect of a primordial magnetic field on the dissipation coefficient in a warm inflation scenario - Gabriella Piccinelli (Centro Tecnológico, FES Aragón, UNAM, México)
Effect of a primordial magnetic field on the dissipation coefficient in a warm inflation scenario (SMFNS2015)
- Gabriella Piccinelli (Centro Tecnológico, FES Aragón, UNAM, México)
16:20 - 16:50
Magnetic fields appear everywhere in the universe. Their widespread presence at high redshifts and very large scales suggests that their origin could be primordial. In particular, their presence during the inflationary epoch can certainly not be ruled out. In the warm inflation scenario, the coupling of the inflaton to other bosonic and fermionic fields gives rise to dissipative effects that modify the inflationary dynamics. Since primordial magnetic fields could have an effect on both the effective inflationary potential and the inflaton decay process, their contribution must be considered together with the finite temperature corrections. We review here their effect on the inflationary potential and present preliminary results of their intervention in the dissipation process.
16:50 Super-Eddington accretion onto neutron stars and black holes - Maciek Wielgus (Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences)
Super-Eddington accretion onto neutron stars and black holes (STARS2015)
- Maciek Wielgus (Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences)
16:50 - 17:30
I will present most recent results, not yet published, concerning the super-Eddington accretion onto neutron stars and black holes. In the case of neutron stars, a new phenomenon is predicted: a levitating atmosphere. In the case of black holes, the Polish Doughnut model for super critical accretion is critically revisited.
17:30 Galileons and Black Holes - Thomas Curtright
Galileons and Black Holes (STARS2015)
- Thomas Curtright
17:30 - 18:00
I will discuss spherically symmetric solutions of hypothetical scalar field "galileon" models, first in flat space-time, and then in the context of general relativity. For the latter, using numerical methods, I find both censored and naked solutions arising from physically reasonable boundary conditions. Both types of solutions are of comparable non-zero measure in terms of the initial conditions. Censored solutions exhibit event horizons, more or less as expected, while naked solutions have curvature singularities without horizons.
18:00 Gas-induced Mergers of Massive Black Holes - Andres Escala (Universidad de Chile)
Gas-induced Mergers of Massive Black Holes (STARS2015)
- Andres Escala (Universidad de Chile)
18:00 - 18:30
Black Hole Astrophysics - Gravitational Radiation - Galactic Mergers
19:00 Welcome reception
Welcome reception
19:00 - 20:00

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