## Advanced Topics in Theoretical Physics -Theoretical physics: From information geometry to out-of-equilibrium classical and quantum matter (Fall 2022)

It is a pleasure to announce this fall's Delta ITP Course Advanced Topics in Theoretical Physics. The course is divided into three 5-week modules, which will covers an introduction to information geometry and its applications, statistical physics of active matter and TBA.

Organization

Each module consists of four lectures and exercise sessions. Lectures will take place on Mondays at 11:15 - 13:00, followed by a study/exercise session from 13:45 - end. At the end of each module there is an exam. All exams are pass/fail, and you need to pass all three exams to receive credit for the course.

We expect that in-person (or hybrid) teaching will be possible, with the location of this course rotating between the three institutes. The first module is in Leiden. Directions to the institutes can be found here: Amsterdam, Utrecht, Leiden. Students who do not have an OV-card from the Dutch government can have their travel costs reimbursed from D-ITP. Please contact the local coordinator (below) for details.

Please register [HERE] before the course begins, even if you do not take the course for credit. We cannot process your grade or send important notices if you do not register.

- MODULE 1:
**Introduction to information geometry and its applications**

**Subodh Patil (Leiden)**

Lectures and exercises: Sept 5, 12, 19, 26 (Oct 3 is Leiden holiday)

Exam: Oct 10

Location: lecture on Sept 5, 12: new Gorlaeus Building DM 115, lecture on Sept 19, 26: Huygens Lab 106, exercise sessions: Huygens Lab 207course information: https://minimalsubtraction.net/introduction-to-information-geometry-and-its-applications/

Abstract: Information geometry in a nutshell, is the geometrization of the study of families of probability distributions. It brings together statistics, information theory and differential geometry in a manner that not only reveals deep and surprising connections between them, but also has wide ranging applications that span topics as diverse as statistical inference and data analysis, machine learning, information theory, quantum measurement theory, statistical physics, biophysics and high energy theory to name only a sample. The lectures will start with an introduction to classical information theory, statistical inference and then introduce the basics of information geometry before covering a broad range of applications in theoretical physics.

- MODULE 2:
**Statistical Physics of Active Matter**

**Sara Jabbari Farouji (Amsterdam)**

Lectures and exercises: Oct 17, 24, 31, Nov 7

Exam: Nov 14

Location: Science Park G5.29Abstract: Active matter refers to any collection of entities that are individually capable of converting stored or ambient free energy to some sort of systematic movement. Examples include all living organisms and their motile constituents such as molecular motors. The interplay between self-propulsion and interactions in active particles leads to emergence of non-equilibrium large-scale structures with novel dynamical properties. In this course, we will present some statistical physics models of active matter with minimal ingredients, which capture the basic phenomenology of non-equilibrium self-organization in active matter. We will combine the principles and tools of non-equilibrium statistical mechanics and particle-based Brownian dynamics simulations of active particles to provide a unifying view of emergent features of dynamical self-organization in active systems.

For these lectures, a basic knowledge of non-equilibrium statistical physics will be helpful. Reading materials and references will be provided throughout the lectures. - MODULE 3:
**Quantum dissipative system**

**Cristiane de Moraïs Smith (Utrecht)**

Lectures from 11.00-13.00 hours: Nov 21, 28, Dec 5, 12

Location: Minnaert building, room 009Exercises from 13.00-17.00 hours:

Nov 21: Executive Building – room Van Lier & Egginkzaal

Nov 28: Buys Ballot Building room 169

Dec 05: Buys Ballot Building room 161

Dec 12-: Buys Ballot Building room 161

Exam: Dec 19Abstract: In this course, we will treat dissipative quantum systems. Usual quantum mechanics is based on canonical quantization, which requires energy conservation. The so-called Caldeira-Leggett model was proposed in the 80’s to describe quantum open systems.

This model couples the system of interest to a reservoir and leads to an effective description after integrating out the bath degrees of freedom. It is based on a path-integral approach, since it involves N+1 degrees of freedom. We will start by discussing Josephson junctions and SQUIDs, which are the paradigmatic examples that led to the Caldeira-Leggett formulation. Then, we will introduce the Caldeira-Leggett model and show that it reproduces a Langevin equation, characteristic of Brownian motion, in the semiclassical limit. Finally, we will perform the full path integral calculation to derive the dynamical reduced density operator, and the one in equilibrium. The last lecture will be about applications of the Caldeira-Legget model, including the more general case involving fractional derivatives, which leads to the concept of a time-glass.Bibliography:

1. Lecture notes, C. Morais Smith (see pdf).

2. An Introduction to Macroscopic Quantum Phenomena and Quantum Dissipation by A. O. Caldeira, Cambridge University Press (2014).

3. R. C. Verstraten, R. F. Ozela, and C. Morais Smith, Time glass: a fractional calculus approach, Phys. Rev. B 103, L180301 (2021); https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.L180301 - CONTACT:
Dr. Lars Fritz

Institute for Theoretical Physics

Utrecht University

Princetonplein 5

3584 CC Utrecht

tel: +31 30 253 3880

e-mail: l.fritz@uu.nlProf. Koenraad Schalm

Instituut-Lorentz for Theoretical Physics

Leiden University

Niels Bohrweg 2

2335 CA Leiden

email: kschalm@lorentz.leidenuniv.nlDr. Wouter Waalewijn

Institute for Theoretical Physics

University of Amsterdam

Science Park 904

1098 XH Amsterdam

e-mail: w.j.waalewijn@uva.nlAdministrative matters:

Annette Ligtenberg

Institute for Theoretical Physics

Utrecht University

Princetonplein 5

3584 CC Utrecht

tel: +31 30 253 5928

e-mail: science.secr.drstp@uu.nl