XII AVOGADRO MEETING <br> on Strings, Supergravity and Gauge Theories
from
Wednesday, 21 December 2016 (08:45)
to
Friday, 23 December 2016 (13:00)
Monday, 19 December 2016
Tuesday, 20 December 2016
Wednesday, 21 December 2016
08:45
Opening

Valentina Giangreco Puletti
Gianluca Grignani
(PG)
Opening
Valentina Giangreco Puletti
Gianluca Grignani
(PG)
08:45  09:00
Room: Aula C, second floor
09:00
Defects in conformal and supersymmetric field theories

Simone Giacomelli
((ICTP Trieste))
Marco Meineri
(EPFL Lausanne)
Defects in conformal and supersymmetric field theories
Simone Giacomelli
((ICTP Trieste))
Marco Meineri
(EPFL Lausanne)
09:00  11:00
Room: Aula C, second floor
In a quantum or statistical field theory, the action of operators on the vacuum describes how a physical system is affected by a probe. Often, the probes are extended objects: the wordline of a heavy particle, a boundary or an interface, etc. We describe some general features of extended probes, in highly symmetric QFTs. We first focus on conformal field theories. We discuss properties of the Operator Product Expansion in the presence of defects and give examples of topological and non topological conformal defects. We then move to the case of supersymmetric theories, in which we can construct defects with twodimensional (or higher) support. We explain how certain kinds of extended probes are able to detect the phases of the theory. Finally, we describe the relevance of defects in constructing a large class of superconformal N=2 theories in four dimensions, and how one can use properties of topological defects in two dimensions to compute the expectation value of line operators in these theories.
11:00
Coffeebreak
Coffeebreak
11:00  11:30
Room: Aula C, second floor
11:30
Defects in conformal and supersymmetric field theories  Discussion session

Stefano Cremonesi
(Durham)
Simone Giacomelli
(ICTP Trieste)
Marco Meineri
(EPFL Lausanne)
Defects in conformal and supersymmetric field theories  Discussion session
Stefano Cremonesi
(Durham)
Simone Giacomelli
(ICTP Trieste)
Marco Meineri
(EPFL Lausanne)
11:30  12:30
Room: Aula C, second floor
12:30
Lunch
Lunch
12:30  14:30
Room: Aula C, second floor
14:30
Soft terms in string compactifications

Susha Parameswaran
(Liverpool)
Francesco Muia
(Oxford)
Soft terms in string compactifications
Susha Parameswaran
(Liverpool)
Francesco Muia
(Oxford)
14:30  16:30
Room: Aula C, second floor
Supersymmetry is a generic prediction of string theory. Given that it is not an exact symmetry of nature, in order to connect string compactifications to particle physics, we must understand how supersymmetry is broken. This issue is intimately related to the moduli stabilisation problem in string theory, as the latter determines the vacuum structure of the theory. Interestingly, SUSYbreaking in string theory is typically soft, which means that the supersymmetric cancellation of quadratic divergences in the Higgs mass endures. Such breaking is then parameterised by soft terms, which roughly determine the masses of superpartners. If SUSYbreaking generates softterms at energy scales accessible to particle accelerators (as expected if lowenergy SUSY is the correct way of addressing the hierarchy problem) then, remarkably, they would directly relate properties of the string compactification to experiments. We will begin by reviewing the motivation and description of soft SUSYbreaking in the MSSM and supergravity, commenting on current constraints from the LHC. We will then describe the main mechanisms for moduli stabilisation, SUSYbreaking and mediation in string theory. Putting these tools together we will illustrate, within the Heterotic and Type IIB theories, interesting possibilities for the softterms in string compactifications. A particular focus will be on the interplay with cosmology, which has been best studied in Type IIB models. The presence of moduli in these compactifications leads to a modification of the standard Big Bang Theory, in which the reheating of the universe is driven by the decay of the lightest modulus. In particular, we will show that such nonstandard cosmological history of the universe plays a crucial role in constraining SUSYbreaking in string models. Interestingly, it turns out that, once all the cosmological constraints are taken into account, it is actually rather difficult to get lowenergy SUSY from string theory. Finally, we will briefly review the cosmological scenarios which could arise from such string compactifications.
16:30
Coffeebreak
Coffeebreak
16:30  17:00
Room: Aula C, second floor
17:00
Soft terms in string compactifications  Discussion session

Susha Parameswaran
(Liverpool)
Francesco Muia
(Oxford)
Michele Cicoli
(BO)
Soft terms in string compactifications  Discussion session
Susha Parameswaran
(Liverpool)
Francesco Muia
(Oxford)
Michele Cicoli
(BO)
17:00  18:00
Room: Aula C, second floor
Thursday, 22 December 2016
09:00
Black hole mergers and gravitational waves

Sebastiano Bernuzzi
(P)
Paolo Pani
(Rome Sapienza)
Black hole mergers and gravitational waves
Sebastiano Bernuzzi
(P)
Paolo Pani
(Rome Sapienza)
09:00  11:00
Room: Aula C, second floor
The broad scope of these lectures is to introduce the basic elements which are necessary to understand the GW signals from a BH binary merger recentlyobserved by LIGO, and to provide the basis of some stateoftheart applications in this rapidlygrowing field. Content i) A GW physics primer. ii) Introduction to the postNewtonian formalism. The case of circular inspiral. iii) Blackhole perturbations and quasinormal modes (QNMs) iv) GWs from a radial plunge of a test particle into a black hole: QNM ringing v) Blackhole spectroscopy: tests of gravity and of nearhorizon physics vi) Numerical Relativity and EffectiveOneBody (EOB) approach
11:00
Coffeebreak
Coffeebreak
11:00  11:30
Room: Aula C, second floor
11:30
Black hole mergers and gravitational waves  Discussion session

Daniele Dorigoni
(Durham)
Sebastiano Bernuzzi
(P)
Paolo Pani
(Rome Sapienza)
Black hole mergers and gravitational waves  Discussion session
Daniele Dorigoni
(Durham)
Sebastiano Bernuzzi
(P)
Paolo Pani
(Rome Sapienza)
11:30  12:30
Room: Aula C, second floor
12:30
Lunch
Lunch
12:30  14:30
Room: Aula C, second floor
14:30
Topological states of matter and nonsupersymmetric dualities

Andrea Amoretti
(Wuerzburg)
Giandomenico Palumbo
(Utrecht)
Topological states of matter and nonsupersymmetric dualities
Andrea Amoretti
(Wuerzburg)
Giandomenico Palumbo
(Utrecht)
14:30  16:30
Room: Aula C, second floor
In the first part of the lecture, we will briefly introduce topological phases of matter and their main properties by employing effective quantum field theories, such as ChernSimons and relativistic fermion theories. In particular, we will review the role of the Dirac theory in these quantum phases by focusing on the fractional quantum Hall effect with filling factor 1/2 (FQHE1/2), where an emergent particlehole symmetry plays a prominent role. The second part of the lecture deals with dualities and their possible application to topological states of matter. Specifically, we will review recent papers where, starting from a relativistic form of flux attachment designed to transmute the statistics of particles, a web of new dualities can be derived. This includes the usual particlevortex duality for bosons as well as the recently discovered counterpart for fermions in the FQHE1/2 and on the surface states of threedimensional topological insulators.
16:30
Coffeebreak
Coffeebreak
16:30  17:00
Room: Aula C, second floor
17:00
Topological states of matter and nonsupersymmetric dualities  Discussion session

Andrea Campoleoni
(Université Libre de Bruxelles)
Andrea Amoretti
(Wuerzburg)
Giandomenico Palumbo
(Utrecht)
Topological states of matter and nonsupersymmetric dualities  Discussion session
Andrea Campoleoni
(Université Libre de Bruxelles)
Andrea Amoretti
(Wuerzburg)
Giandomenico Palumbo
(Utrecht)
17:00  18:00
Room: Aula C, second floor
20:00
20:00  23:00
Friday, 23 December 2016
09:00
Exact results for superconformal field theories

Antonio Sciarappa
(KIAS Seoul)
Marco Baggio
(KUL Leuven)
Exact results for superconformal field theories
Antonio Sciarappa
(KIAS Seoul)
Marco Baggio
(KUL Leuven)
09:00  11:00
Room: Aula C, second floor
One of the most widely used approaches to study interacting quantum field theories is perturbation theory, where physical quantities are expressed as a series expansion in some small parameter. Despite its many successes, the perturbative approach cannot be used to study important physical phenomena like confinement and chiral symmetry breaking in QCD for which nonperturbative and strongcoupling effects play a key role. While these are still largely open problems, in the last few years the field has witnessed tremendous progress in understanding the nonperturbative and strongly coupled behaviors of many interesting quantum field theories, especially in the supersymmetric context where we can now compute several observables of interest, such as partition functions and correlation functions, exactly in the coupling constant. In these lectures we will present some of these recent developments, focusing in particular on four dimensional N=2 supersymmetric field theories. After introducing the theories of interest, we will discuss how these are related to integrable systems and how this correspondence can be used to compute their partition function around a generic strongcoupling point. In the case where these theories also enjoy conformal symmetry, the partition function encodes detailed information about correlation functions of chiral operators. We will describe how the 3point functions of chiral primaries can be computed exactly using techniques from localization and the tt* equations.
11:00
Coffeebreak
Coffeebreak
11:00  11:30
Room: Aula C, second floor
11:30
Exact results for superconformal field theories  Discussion session

Antonio Sciarappa
(KIAS Seoul)
Marco Baggio
(KUL Leuven)
Davide Cassani
(LPTHE Jussieu)
Exact results for superconformal field theories  Discussion session
Antonio Sciarappa
(KIAS Seoul)
Marco Baggio
(KUL Leuven)
Davide Cassani
(LPTHE Jussieu)
11:30  12:30
Room: Aula C, second floor