Registration will be on March 30th from 8 to 9 am
The banquet will be on March 30th at 8 pm in Guappa
Speech by Jorge Pullin on occasion of Rodolfo Gambini’s 70th birthday
Plenary Talks
Hermann Nicolai 

On conformal anomalies

Alejandro Pérez 

Quantum gravity and the cosmological constant

Achilleas Porfyriadis 

Observational implications of the Kerr/CFT correspondence
I will review recent work which utilizes the Kerr/CFT correspondence to compute explicit analytical gravitational waveforms for extrememassratioinspirals in the nearhorizon region of nearextreme Kerr black holes. The conformal symmetries imply a variety of qualitatively new and potentially observable signals in the gravitational wave window. I will also explain how Kerr/CFT has been used to find analytically the null geodesics which extend from the nearhorizon region out to a distant observatory. This computation lays the groundwork for an exploration of the consequences of Kerr/CFT on observational signals in the optical window.

Rafael Porto 

Black Holes: ‘The aura of the miraculous’

Jorge Zanelli 

Cosmic Censorship as a Quantum Effect

Carmen Núñez 

The Odd story of alphaprime corrections
I will discuss the Tduality structure of the ﬁrst order alphaprime corrections in the string eﬀective actions. Deformations of Double Field Theory provide a covariant gauge symmetry principle that organizes these corrections and allows to obtain the four derivative corrections to bosonic and heterotic strings, HSZ theory, halfmaximal gauged supergravities, etc.

Abhay Ashtekar 

Quantum Gravity in the sky? Interplay between fundamental theory and Observations
Thanks to the spectacular observational advances since the 1990s, a ‘standard model’ of the early universe has now emerged. However, since it is based on quantum field theory in curved spacetimes, it is not applicable in the Planck regime. Using techniques from loop quantum gravity, the theory can be extended over the 12 orders of magnitude in density and curvature from the onset of inflation all the way back to the Planck regime, providing us with a possible completion of the standard model. Contrary to a widespread belief, the resulting preinflationary dynamics can have observational consequences. Thus, there is now an an interesting interplay between fundamental theory and observations. The talk will provide a broad overview of these results and provide the background material for Ivan Agullo’s talk that will discuss further phenomenological consequences of loop quantum cosmology.

Iván Agullo 

The phenomenology of a loop quantum cosmologymotivated bounce preceding inflation
Loop quantum cosmology has become a robust framework to describe the highest curvature regime of the early universe. In this framework, inflation is preceded by a bounce replacing the big bang singularity. This talk will explore the consequences for to the inflationary predictions for the primordial spectrum of cosmological perturbations that this preinflationary phase of the universe introduces. The impact of the bounce on nonGaussianity and the exciting relation to the observed large scale anomalies in the CMB will be discussed. This presentation will extend a previous talk by A. Ashtekar on the same topic, and will provide a complementary angle to the subject.

Matías Zaldarriaga 

What we might hope to learn about early Universe physics from upcoming measurements

Juan Maldacena 

Quantum Mechanical models for near extremal black holes
We describe some simple quantum mechanical models that have features very similar to near extremal black holes. These models have an emergent conformal symmetry which is slightly broken in a manner that is very similar to that of near extremal black holes. In addition, the models are maximally chaotic, such as black holes are.

Javier Olmedo 

Black holes in loop quantum gravity
In this contribution I will provide my point of view about black holes in loop quantum gravity and recent advances.

Victor Rivelles 

A Gauge Theory Formulation for Continuous Spin Particles
Continuous spin particles are one of the irreducible representations of the Poincare group. Its properties are largely unknown since standard gauge theories techniques have been shown to be problematic. Recently a gauge theory formulation on a cotangent bundle was found. We will discuss its properties and shortcomings.

Nathan Berkovits 

Twistors and the Superstring

Pedro Vieira 

Smatrix and Conformal Bootstrap

Daniel Harlow 

Symmetries in Quantum Field theory and Gravity
I use the AdS/CFT correspondence to study a set of standard conjectures about symmetry and quantum gravity. I’ll give a general argument that all CFT global symmetries, discrete or continuous, must arise asymptotically from gauge symmetries in the bulk. Conversely, I’ll argue that any global symmetry in the bulk would lead to an inconsistency in the CFT. I’ll also argue that the correspondence requires dynamical objects that transform in all finitedimensional irreducible representations of the gauge group. An essential point, which I’ll dwell on at some length, is precisely defining what we mean by gauge and global symmetries in the bulk and boundary. Time permitting, I will also discuss the compactness of internal global symmetry groups in quantum field theory.

Eugenio Bianchi 

Entanglement in loop quantum gravity

Short Talks
Martín Reiris 

Applications of comparison geometry a la BakryÉmery to static and stationary solutions

Ernesto Frodden 

Charges and Gauge Symmetries for Gravity in the First Order Formalism
A new derivation of surface charges for 3+1 gravity in the tetradconnection variables is obtained. The use of cosmological constant and the consideration of spacetime with asymptotically constant curvature requires an Euler term in the action, it regularize the action and the charges derived in the formalism. As a preliminary check we show that, when gauge symmetries are promoted to exact symmetries, the local conservation of surface charges implies the first law of black hole mechanics for the KerrNewman (anti) de Sitter family of solutions without relying on the asymptotics structure of the spacetime.

Ángel Rincón 

Scale dependent Einstein(power)Maxwell black hole in (2+1) dimensions
In this work we investigate the scale dependence at the level of the effective action of charged black holes in EinsteinMaxwell as well as in Einstein powerMaxwell theories in (2+1)dimensional spacetimes without a cosmological constant. Self consistent solutions for the lapse function, the electromagnetic coupling, the electric field and the Newton’s coupling are found. Those results are compared to the wellknown solution for constant couplings. Moreover, asymptotic behavior as well as thermodynamic properties are investigated.

Raju Roychowdhury 

Imprints of Dirac Structure in Emergent Gravity and a geometric Tdual avatar
Darboux theorem and Moser lemma in symplectic geometry are the two essential ingredients of emergent gravity. Generalized geometry naturally provides the framework for such a systematic approach to nonsymmetric metric gravity and gives rise to the group of Courant automorphism for the Pontryagin bundle. As further consequences of generalized geometry and Courant algebroid structure we found the imprints of Dirac structure in emergent gravity. The nondegeneracy and closure of the symplectic 2form induce an interesting geometric structure namely the Big isotropic structure on the base manifold M and it is possible to associate weak Hamiltonian vector fields corresponding to such structure. Finally we propose a Tdual avatar of emergent gravity implemented between oriented circle bundles and this duality can be realised in terms of Gysin sequence in the cohomology. The inbuilt Dirac structure makes it possible to realise diffeomorphism in the target space in the Tdual picture, as well.

Nikolaos Dimakis 

Minisuperspace Quantization of the ReissnerNordström geometry
We start from a static, spherically symmetric spacetime in the presence of an electrostatic field and construct the minisuperspace Lagrangian that reproduces the well known Reissner – Nordström solution. We identify the classical integrals of motion that are to be mapped to quantum observables and which are associated with the mass and charge. Their eigenvalue equations are used as supplementary conditions to the WheelerDeWitt equation and a link is provided between the existence an horizon and to whether the spectrum of the observables is fully discrete or not. For each case we provide an orthonormal basis of states as emerges through the process of canonical quantization.

Victor Santos 

Quasinormal frequencies of selfdual black holes
In this walk I will discuss the computation of the quasinormal modes (QNMs) of scalar perturbations around a simplified black hole model constructed from a semiclassical analysis of loop quantum gravity (LQG), called selfdual black hole. The solution depends on a free dimensionless parameter $P$ known as the polymeric parameter and also on the area gap of LQG. We compute the QN frequencies using the sixth order WKB approximation method and compare them with numerical solutions of the ReggeWheeler equation, and show they are in agreement with the Schwarzschild frequencies in the classical limit.

Albert Petrov 

The CPTeven Lorentzbreaking term in QED and its ambiguities
In this talk, we discuss the dynamical generation of the CPTeven aetherlike Lorentzbreaking term in the extended Lorentzbreaking QED, whose action involves, besides of the usual coupling of the QED, also the Lorentzbreaking magnetic coupling, and show that despite the aether term is superficially divergent, really it is finite and ambiguous, with two different ambiguities can arise, with one of these ambiguities contributes to the generalized AdlerBellJackiw anomaly. We show that this term continues to be ambiguous at the finite temperature as well.

Alejandro Satz 

Entanglement entropy and mutual information of smeared field observables
We define the entanglement entropy associated with a finite, discrete subalgebra of smeared field observables. Unlike the “geometric” entanglement entropy associated to the field in a spatial region, this is a welldefined finite quantity which, together with the mutual information between subalgebras defined from it, be used to probe in a simple way the correlations and entanglement of quantum fields in situations of physical interest. Applications in flat and cosmological backgrounds are presented, and the relationship with the geometric entropy scaling as the area of a region is discussed.

Ricardo Medina 

Graviton and gluon amplitudes from first principles
Graviton and gluon tree level amplitudes are studied from minimal physical assumptions such as Poincaré and gauge symmetry as well as unitarity. These assumptions lead to a surprisingly restrictive set of linear equations for the coefficients of those amplitudes. As a result this shows how gluon and graviton amplitudes are related in many field and string theories, explaining and extending several known results. Also, by a systematic analysis exceptional graviton amplitudes can be found, which cannot be related to gluon amplitudes.

Henrique Gomes 

Timeless Quantum Gravity
The Wheeler DeWitt equation is known to have several issues, both technical and conceptual. In this talk, I will describe an alternative construction of a global wavefunction which can evade some of its problems. Time allowing, I will showcase the construction with a toy model.

Fernando Izaurieta 

Nonminimal couplings, torsion and gravitational waves
Nonminimal couplings with scalar fields in general are sources of torsion in gravity, even in the absence of fermions. It will be analysed how gravitational waves could provide a mechanism to detect this torsion.

Aureliano Skirzewski 

Effective FRW Radiation Dominated Era
We compute effective equations of the quantum FRW flat universe in the radiation dominated era at order $\hbar$, described in terms of Ashtekar variables employing a new method for the geometrical formulation of quantum mechanics. Additional terms of quantum nature correct the classical equations of motion. As a consequence, the initial singularity of the classical model is removed and a Big Bouncing scenario takes its place. We also obtain an expression for the effective action of the model in terms of higher curvature invariants, leading us to corrected Einstein equations for more general contexts

Oscar Castillo 

A polynomial affine theory of gravity
We build up an affine model of gravity under the presents of polynomial structure and diffeomorphisms invariance. The resulting model is a “rigid” theory which presents several advantage which might solve known problems related with the quantization procedure. We show that in a sector, the field equations are a known generalization of those of General Relativity. We obtain some exact solutions in these sector, and also discuss how to couple scalar fields to these model.

Posters
Carlos Alberto Almeida 

On quantum gravity deviations in the luminosity of black holes
Noncommutative corrections to the classical expression for the fuzzy sphere area are found out through the asymptotic expansion for its heat kernel trace. As an important consequence, some quantum gravity deviations in the luminosity of black holes must appear. We calculate these deviations for a static, spherically symmetric, blackhole with a horizon modeled by a fuzzy sphere. The results obtained could be verified through the radiation of black holes formed in the Large Hadron Collider (LHC).

Maria Jose Guzman 

The teleparallel equivalent of general relativity: constraint algebra
The teleparallel equivalent of general relativity is an alternative description of gravity, which uses the tetrad field, instead of the metric tensor, as the dynamical variable. Its Lagrangian depends on the torsion of the Weitzenb\”{o}ck connection, which is curvatureless and represents a spacetime with absolute parallelism. We write the Lagrangian as a quadratic form of the coefficients of anholonomy of the orthonormal frames (vielbeins), in order to study the algebra of constraints. It is analyzed the structure of eigenvalues of the multiindex matrix entering the linear relation between canonical velocities and momenta to obtain the set of primary constraints. The canonical Hamiltonian is then built with the MoorePenrose pseudoinverse of that matrix, to then derive the secondary constraints. All the set of constraints completes a first class algebra; and it is obtained the ADM algebra of general relativity as a subalgebra.

Edison Montoya 

Qualitative Approach to Loop Quantum Cosmology
We justify the importance of the Bianchi IX model in the description of the universe. Afterwards, we study the modication of the mixmaster behavior of Bianchi IX universe induced by the loop quantum eects. It is shown that there is an isotropization process, some classical solutions are discarded and there is no chaotic behavior.
