Program

Registration will be on March 30th from 8 to 9 am

x March 30. 2017 – Day One March 31. 2017 – Day Two April 1. 2017 – Day Three
9:00am – 9:45am

Morning Chair: Pullin

Hermann Nicolai

On conformal anomalies

Slides   Audio

Morning Chair: Zanelli

Abhay Ashtekar

Quantum Gravity in the sky? Interplay between fundamental theory and Observations

Slides   Audio

Morning Chair: Agullo

Nathan Berkovits

Twistors and the Superstring

Slides   Audio

9:45am – 10:30am Alejandro Pérez

Quantum gravity and the cosmological constant

Slides   Audio

Iván Agullo

The phenomenology of a loop quantum cosmology-motivated bounce preceding inflation

Slides   Audio

Pedro Vieira

S-matrix and Conformal Bootstrap

Slides   Audio

10:30am – 11:00am Coffee Break Coffee Break Coffee Break
11:00am – 11:45am Achilleas Porfyriadis

Observational implications of the Kerr/CFT correspondence

Slides   Audio

Matías Zaldarriaga

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

Slides   Audio

Daniel Harlow

Symmetries in Quantum Field theory and Gravity

Slides   Audio

11:45am – 12:30pm Rafael Porto

Black Holes: ‘The aura of the miraculous’

Slides   Audio

Juan Maldacena

Quantum Mechanical models for near extremal black holes

Slides   Audio

Eugenio Bianchi

Entanglement in loop quantum gravity

Slides   Audio

12:30pm – 2:30pm Lunch Lunch
2:30pm – 3:00pm Afternoon Chair: Rivelles

Jorge Zanelli

Cosmic Censorship as a Quantum Effect

Slides   Audio

Afternoon Chair: Núñez

Javier Olmedo

Black holes in loop quantum gravity

Slides   Audio

3:00pm – 3:30pm Carmen Núñez

The Odd story of alpha-prime corrections

Slides   Audio

Victor Rivelles

A Gauge Theory Formulation for Continuous Spin Particles

Slides   Audio

3:30pm – 4:00pm Coffee Break
Poster Session
Coffee Break
Poster Session
4:00pm – 6:00pm Short Talks (15 min each)
Chair: Olmedo

Ernesto Frodden:   Charges and Gauge Symmetries for Gravity in the First Order Formalism

Slides   Audio



Ángel Rincón:   Scale dependent Einstein-(power)-Maxwell black hole in (2+1) dimensions

Slides   Audio



Raju Roychowdhury:   Imprints of Dirac Structure in Emergent Gravity and a geometric T-dual avatar

Slides   Audio



Nikolaos Dimakis:   Mini-superspace Quantization of the Reissner-Nordström geometry

Slides   Audio



Victor Santos:   Quasinormal frequencies of self-dual black holes

Slides   Audio

Short Talks (15 min each)
Chair: Porto

Martín Reiris:   Applications of comparison geometry a la Bakry-Émery to static and stationary solutions.

Slides   Audio



Alejandro Satz:   Entanglement entropy and mutual information of smeared field observables

Slides   Audio



Ricardo Medina:  Graviton and gluon amplitudes from first principles

Slides   Audio



Henrique Gomes:  Timeless Quantum Gravity

Slides   Audio



Aureliano Skirzewski:  Effective FRW Radiation Dominated Era

Slides   Audio



Oscar Castillo:   A polynomial affine theory of gravity

Slides   Audio


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 extreme-mass-ratio-inspirals in the near-horizon region of near-extreme 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 near-horizon 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 alpha-prime corrections

I will discuss the T-duality structure of the first order alpha-prime 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, half-maximal 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 space-times, 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 wide-spread belief, the resulting pre-inflationary 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 cosmology-motivated 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 pre-inflationary phase of the universe introduces. The impact of the bounce on non-Gaussianity 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

S-matrix 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 finite-dimensional 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 Bakry-Émery 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 tetrad-connection 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 Kerr-Newman (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 Einstein-Maxwell as well as in Einstein- power-Maxwell theories in (2+1)-dimensional space-times 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 well-known 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 T-dual 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 non-symmetric 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 non-degeneracy and closure of the symplectic 2-form 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 T-dual 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 T-dual picture, as well.


Nikolaos Dimakis

Mini-superspace Quantization of the Reissner-Nordström geometry

We start from a static, spherically symmetric space-time in the presence of an electrostatic field and construct the mini-superspace 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 Wheeler-DeWitt 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 self-dual 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 self-dual 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 Regge-Wheeler equation, and show they are in agreement with the Schwarzschild frequencies in the classical limit.


Albert Petrov

The CPT-even Lorentz-breaking term in QED and its ambiguities

In this talk, we discuss the dynamical generation of the CPT-even aether-like Lorentz-breaking term in the extended Lorentz-breaking QED, whose action involves, besides of the usual coupling of the QED, also the Lorentz-breaking 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 Adler-Bell-Jackiw 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 well-defined 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 wave-function which can evade some of its problems. Time allowing, I will showcase the construction with a toy model.


Fernando Izaurieta

Non-minimal couplings, torsion and gravitational waves

Non-minimal 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

Non-commutative 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, black-hole 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 multi-index 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 Moore-Penrose pseudo-inverse 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 sub-algebra.


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 modi cation of the mixmaster behavior of Bianchi IX universe induced by the loop quantum e ects. It is shown that there is an isotropization process, some classical solutions are discarded and there is no chaotic behavior.