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Theory Lectures by Young Researchers



Th-LYR is a series of introductory web-lectures on specific research topics in Theoretical Physics, spanning Cosmology, Lattice Gauge Theory, QFT, String Theory, and Mathematical Physics. The lectures will be given by young researchers to young researchers in an informal and stimulating environment with extensive space for questions and discussions.
Organizers: Claudio Bonanno, Alessio Caddeo, Carlo Alberto Cremonini, Matteo Maria Maglio, Rocco Rollo (GGI Post-Docs)

List of Lectures

Registration Form

For the Future Seminars look at the List


Marco Piva - National Institute of Chemical Physics and Biophysics (NICPB), Tallin
Higher-derivative quantum field theories, unitarity and quantum gravity
15 Oct 2021 - 10:00

These lectures aim to clarify several aspects of higher-derivative quantum field theories, their issues and how to circumvent them. Special attention will be given to quantum gravity. After reviewing general definitions we discuss the role of higher derivatives in both effective field theories and fundamental ones. Focusing on the latter, we explore the class of theories suitable for quantum gravity, iscuss their features and the issues with unitarity. Finally, we show how to reconcile renormalizability and unitarity by means of purely virtual quanta.

Poster
Marco Piva - National Institute of Chemical Physics and Biophysics (NICPB), Tallin
Higher-derivative quantum field theories, unitarity and quantum gravity
14 Oct 2021 - 10:00

These lectures aim to clarify several aspects of higher-derivative quantum field theories, their issues and how to circumvent them. Special attention will be given to quantum gravity. After reviewing general definitions we discuss the role of higher derivatives in both effective field theories and fundamental ones. Focusing on the latter, we explore the class of theories suitable for quantum gravity, discuss their features and the issues with unitarity. Finally, we show how to reconcile renormalizability and unitarity by means of purely virtual quanta.

Poster
Lorenzo Bartolini (Henan U.)
The holographic approach to non-perturbative QCD and baryon physics – Lecture 2
14 Sep 2021 - 10:00

The Gauge/Gravity duality introduced a new tool for investigating QFTs in non perturbative regimes: the most phenomenologically relevant example of these theories is QCD at low energy (at the scale of nuclear physics), whose spectrum of bound states ranges from glueballs, to mesons, to complicated atomic nuclei. In these lectures we will review the Gauge/Gravity duality and discuss its extension to (almost) QCD, illustrating the top-down model of Witten-Sakai-Sugimoto: we will show the emergence of baryons from the model, and how to use it to compute observables that can prove themselves challenging via other techniques.

Poster
Lorenzo Bartolini (Henan U.)
The holographic approach to non-perturbative QCD and baryon physics – Lecture 1
13 Sep 2021 - 10:00

The Gauge/Gravity duality introduced a new tool for investigating QFTs in non perturbative regimes: the most phenomenologically relevant example of these theories is QCD at low energy (at the scale of nuclear physics), whose spectrum of bound states ranges from glueballs, to mesons, to complicated atomic nuclei. In these lectures we will review the Gauge/Gravity duality and discuss its extension to (almost) QCD, illustrating the top-down model of Witten-Sakai-Sugimoto: we will show the emergence of baryons from the model, and how to use it to compute observables that can prove themselves challenging via other techniques.

Poster
Davide Vadacchino (Trinity College, Dublin)
Lattice QCD: a primer of methods and results
29 Jun 2021 - 11:00

The lattice regularization of Quantum Field Theories is a first-principles approach that allows to explore their non-perturbative regime via computer simulations. Over the years, it has provided valuable inputs to experimental studies and has contributed to the understanding of some of the deepest features of strongly-interacting field theories. The constant improvement of algorithms and computational power makes the lattice regularization an essential tool in the hands of the theoretical physicists of the future. In these lectures, the theoretical foundations of this approach will be reviewed, and some of the main results and currently open problems will be discussed.

Slides

Poster
Davide Vadacchino (Trinity College, Dublin)
Lattice QCD: a primer of methods and results
28 Jun 2021 - 11:00

The lattice regularization of Quantum Field Theories is a first-principles approach that allows to explore their non-perturbative regime via computer simulations. Over the years, it has provided valuable inputs to experimental studies and has contributed to the understanding of some of the deepest features of strongly-interacting field theories. The constant improvement of algorithms and computational power makes the lattice regularization an essential tool in the hands of the theoretical physicists of the future. In these lectures, the theoretical foundations of this approach will be reviewed, and some of the main results and currently open problems will be discussed.

Slides

Poster
Angelo Ricciardone - Dipartimento di Fisica e Astronomia “G. Galilei”, Padova University
Primordial Gravitational waves and interferometers
18 Jun 2021 - 11:00

Gravitational Waves (GWs) represent a unique tool to explore the physics and the microphysics of the universe. After the GW direct detections by the LIGO/Virgo collaboration, the next target of modern cosmology is the detection of Stochastic Gravitational Wave Backgrounds (SGWB), both of cosmological and astrophysical origin. In this lectures, I will present early universe scenarios that can be probed with future GW detectors; in particular I will show how the LISA and Einstein Telescope (ET) interferometers, in addition to the detection and characterization of GWs of astrophysical origin, will give compelling information about the cosmological background of GWs. I will discuss the main tools and observables to deal with GW physics at interferometers.

Poster

Video
Angelo Ricciardone - Dipartimento di Fisica e Astronomia “G. Galilei”, Padova University
Primordial Gravitational waves and interferometers
17 Jun 2021 - 11:00

Gravitational Waves (GWs) represent a unique tool to explore the physics and the microphysics of the universe. After the GW direct detections by the LIGO/Virgo collaboration, the next target of modern cosmology is the detection of Stochastic Gravitational Wave Backgrounds (SGWB), both of cosmological and astrophysical origin. In this lectures, I will present early universe scenarios that can be probed with future GW detectors; in particular I will show how the LISA and Einstein Telescope (ET) interferometers, in addition to the detection and characterization of GWs of astrophysical origin, will give compelling information about the cosmological background of GWs. I will discuss the main tools and observables to deal with GW physics at interferometers.

Poster

Video
Sara Bonansea
Defects in conformal field theory and holography
28 May 2021 - 11:00

The general study of defects has relations with the physics of almost every field theory. Defects can be introduced into a conformal field theory as means to make contact with the real world, reducing the total amount of symmetry. The broken conformal symmetries relax some of the constraints put on the correlation functions and defects can be used as probes to study the dynamics of a theory. In the first part of these lectures, I will give some hints on the bootstrap program for defect conformal field theories. Furthermore, I will focus on a particular defect version of N=4 Super Yang-Mills which has a holographic realization in terms of a D3-probe-D5 brane system. In this setup, I will present some particular results for local and non-local observables achieved with different techniques.

Poster

Video
Sara Bonansea
Defects in conformal field theory and holography
27 May 2021 - 11:00

The general study of defects has relations with the physics of almost every field theory. Defects can be introduced into a conformal field theory as means to make contact with the real world, reducing the total amount of symmetry. The broken conformal symmetries relax some of the constraints put on the correlation functions and defects can be used as probes to study the dynamics of a theory. In the first part of these lectures, I will give some hints on the bootstrap program for defect conformal field theories. Furthermore, I will focus on a particular defect version of N=4 Super Yang-Mills which has a holographic realization in terms of a D3-probe-D5 brane system. In this setup, I will present some particular results for local and non-local observables achieved with different techniques.

Poster

Video
Luigi Tizzano
(Simons Center for Geometry and Physics, SUNY, Stony Brook, NY)
Aspects of Generalized Global Symmetries and Anomalies
Lecture II
13 May 2021 - 16:00

Abstract
I will review some recent results on the dynamics of quantum field theories based on a renewed understanding of global symmetries and their anomalies.

Poster

Video
Luigi Tizzano
(Simons Center for Geometry and Physics, SUNY, Stony Brook, NY)
Aspects of Generalized Global Symmetries and Anomalies
Lecture I
11 May 2021 - 16:00

Abstract
I will review some recent results on the dynamics of quantum field theories based on a renewed understanding of global symmetries and their anomalies.

Poster

Video
Luigi Guerrini - Università di Parma & INFN Parma
Localization of Supersymmetric gauge theories in three dimensions
30 Apr 2021 - 11:00

Supersymmetric Quantum Field Theories provide an exciting arena for exploring physics in the strong coupling regime. Supersymmetric localization has turned out to be a formidable tool for making progress in this direction. The goal of these lectures is to provide a concrete example of supersymmetric localization in the context of three-dimensional gauge theories. I will first review the basic idea of localization in the finite-dimensional case. I will then show an application of this idea to supersymmetric Chern-Simons matter theories. In particular, I will explain how matrix models capture the partition function of these theories.

Slides

Poster

Video
Luigi Guerrini - Università di Parma & INFN Parma
Localization of Supersymmetric gauge theories in three dimensions
29 Apr 2021 - 11:00

Supersymmetric Quantum Field Theories provide an exciting arena for exploring physics in the strong coupling regime. Supersymmetric localization has turned out to be a formidable tool for making progress in this direction. The goal of these lectures is to provide a concrete example of supersymmetric localization in the context of three-dimensional gauge theories. I will first review the basic idea of localization in the finite-dimensional case. I will then show an application of this idea to supersymmetric Chern-Simons matter theories. In particular, I will explain how matrix models capture the partition function of these theories.

Slides

Poster

Video
Paolo Benincasa - Instituto de Fisica Teorica (IFT), Madrid
Cosmology and Geometry at the Boundary - Lecture II
13 Apr 2021 - 11:00

Cosmological observables, such as temperature fluctuations in the CMB and density fluctuations in the distribution of galaxies, can be traced back to the end of inflation where they are encoded in quantum correlations, and the wavefunction of the universe which generates them, at a space-like boundary of a quasi-dS space-time. These lectures will focus on a novel approach to construct the wavefunction of the universe from boundary data only and extract from them physical information. We will learn about its analytic structure, the interpretation of the singularity coefficients as physical processes, including scattering processes in flatspace, as well as a first-principle formulation in terms of combinatorial-geometrical objects which, together to provide new computational tools, provide a window on the basic rules behind cosmological processes.

Poster

Video
Paolo Benincasa - Instituto de Fisica Teorica (IFT), Madrid
Cosmology and Geometry at the Boundary - Lecture I
12 Apr 2021 - 11:00

Cosmological observables, such as temperature fluctuations in the CMB and density fluctuations in the distribution of galaxies, can be traced back to the end of inflation where they are encoded in quantum correlations, and the wavefunction of the universe which generates them, at a space-like boundary of a quasi-dS space-time. These lectures will focus on a novel approach to construct the wavefunction of the universe from boundary data only and extract from them physical information. We will learn about its analytic structure, the interpretation of the singularity coefficients as physical processes, including scattering processes in flatspace, as well as a first-principle formulation in terms of combinatorial-geometrical objects which, together to provide new computational tools, provide a window on the basic rules behind cosmological processes.

Poster

Video
Lucrezia Ravera - Politecnico di Torino (DISAT)
Geometric Approach to Supergravity II
26 Mar 2021 - 11:00

Abstract

The construction of supergravity theories from the technical point of view is a non-trivial task. In particular, complications arise from the fact that fermionic representations are involved. It is therefore particularly useful to find an efficient method to deal with the technical labor in formulating supergravity theories. In these lectures we will explore the geometric (aka rheonomic) approach to supergravity theories in superspace, which allows a complete geometrical interpretation of supersymmetry.



Slides

Poster

Video
Lucrezia Ravera - Politecnico di Torino (DISAT)
Geometric Approach to Supergravity I
25 Mar 2021 - 11:00

Abstract

The construction of supergravity theories from the technical point of view is a non-trivial task. In particular, complications arise from the fact that fermionic representations are involved. It is therefore particularly useful to find an efficient method to deal with the technical labor in formulating supergravity theories. In these lectures we will explore the geometric (aka rheonomic) approach to supergravity theories in superspace, which allows a complete geometrical interpretation of supersymmetry.



Slides

Poster

Video