28.03.2019, 15:30  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Structure from turbulence, or why you might want to care about plasma physics even if you are not a plasma physicist

Ilya Y. Dodin (Princeton University)

Turbulence has always been a tough subject to study. Interestingly though, typical turbulence equations are similar in form to those that govern nondegenerate quantum plasmas, which are easier to... 

04.02.2019, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Stability and instability issues for Vlasov-like equations in gravitational kinetic theory

Mohammed Lemou (IRMAR Rennes, France)

I will start by giving a short overview of the history around stability and instability issues in gravitational systems driven by kinetic equations. Conservations properties and families of... 

31.01.2019, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Classical and Quantum impulsive Scattering

Herbert Balasin (TU Wien)

Using the framework of Colombeau's generalized functions, I will discuss the motion of both the classical as well as the quantum motion of a particle in an impulsive background.

17.01.2019, 11:00  –  Albert-Einstein-Institut, Raum 1.63
Seminar Geometry and Physics

An elementary introduction to MHD equations

Huali Zhang (AEI)

Magnetohydrodynamics (MHD) is the study of the dynamics and magnetic properties of electrically conducting fluids. In this talk, we will give a brief derivation of MHD equations, and also introduce... 

10.01.2019, 11:00  –  Albert-Einstein-Institut, Raum 1.63
Seminar Geometry and Physics

Asymptotically flat vacuum asymptotics: Things that remain to be done

Helmut Friedrich (AEI)

In the last 30 years an enormous amount of work has been done on the existence and global structure of asymptotically flat solutions to Einstein's field equations. Many of these contributions are in... 

13.12.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

The Berry Phase: Introduction and Examples

Lukas Böke (AEI - ETH)

The Berry phase was introduced by Michael Berry in the 80s, and a little later an elegant description in terms of holonomy was observed by Barry Simon. We introduce the Berry phase and the Berry-Simon... 

29.11.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Radiation Memory

Jeff Winicour (University of Pittsburgh)

I will review results about linear and nonlinear radiation memory for electromagnetic and gravitational fields and present some new results for the collision of black holes.

22.11.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Introduction to the Wigner transform

Jérémie Joudioux (AEI)

The Wigner transform was introduced at the beginning of the 30s to understand quantum corrections to classical statistical mechanics. It has then been used in optics to perform analysis in phase space... 

15.11.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Helicity and spin in Maxwell theory and linearized gravity

Sajad Aghapour (Sharif University of Technology, Tehran, and AEI)

The classical definitions of helicity, spin and orbital angular momenta of the electromagnetic field in free space have been improved in recent years in theoretical optics, stimulated by experiments... 

08.11.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Using the geometric optics approach to connect the Dirac equation to the linearised MPD equations

Lukas Böke (AEI)

We present a correspondence, established in papers by R. Rüdiger and J. Audretsch, between quantum mechanical equations of motion and classical equations of spinning massive particles in a... 

01.11.2018, 11:00  –  Albert-Einstein-Institut, Raum 0.01
Seminar Geometry and Physics

Conservation laws for spinning fields

Lars Andersson

Noether's theorem states that for a Lagrangian field theory, symmetries of the action gives rise to conserved currents and charges. The most well-known symmetries are those which arise from Killing... 

06.07.2017, 14:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

A General Definition of Conserved Quantities in General Relativity

Sajad Aghapour (IPM, Teheran)

In this talk I will review a paper by Zoupas and Wald which summarizes the proposal for a general definition of "conserved quantities" in General Relativity and other theories of gravity developed by... 

22.06.2017, 14:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

Introduction to conformal Killing forms

Andreas Hermann

Conformal Killing p-forms are a generalization of conformal Killing vector fields on semi-Riemannian manifolds. In this talk we review some known properties of conformal Killing p-forms. We describe... 

14.06.2017, 15:30 Uhr  –  Albert Einstein Institute, Room 0.01
Seminar Geometry and Physics

Applications of PDE compatibility complexes in relativity

Igor Khavkine

I will discuss the Killing operator (K_{ab}[v] = \nabla_a v_b + \nabla_b v_a) on a (pseudo-)Riemannian manifold as an overdetermined PDE and its (formal) compatibility complex. It has been observed... 

08.06.2017, 14:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

Potentials and conservation laws

Lars Andersson

I will discuss how Hertz potentials can be used to construct conservation laws for massless fields including Maxwell and linearized gravity.

01.06.2017, 14:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

Electromagnetic duality in linearized gravity

Cedric Troessaert

I will review how, in the Hamiltonian formalism, one use a double potential formalism to obtain a manifestly duality invariant description of linearized gravity.

20.04.2017, 14:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

Symmetries and hidden symmetries of Maxwell theory

Lars Andersson

Maxwell's theory of electromagnetism is a relativistic field theory on Minkowski space, and is symmetric under the 10-dimensional Poincare group of isometries of Minkowski space. However, it admits... 

31.01.2017, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Introduction to Supergravity

Olof Ahlén

Supersymmetry has been a very active research area in both elementary particle physics as well as models for quantum gravity. In this talk, I will outline the motivation for analyzing supersymmetric... 

13.12.2016, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Higher conserved currents

Igor Khavkine

A conserved current for a PDE in $n$-variables can be thought of as a field dependent $(n-1)$-form that is closed on solutions. A similar definition can also be made in other form degrees. A field... 

29.11.2016, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Action principles and conserved currents, continued

Lars Andersson

I will introduce the notions of Noether current and Noether charge for a Lagrangian field theory.

References:
Lee and Wald, Local symmetries and constraints, JMP 1990
Iyer and Wald, Some properties of... 

22.11.2016, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

A short introduction to the basics of the Noether theorem and its application

Michael Jung

I will start with an infinitesimal symmetry transformation as a diffeomorphism and derive the Noether-current. The setting is a compact domain in the flat space and just with one scalar field and one... 

15.11.2016, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Action principles and conserved currents

Lars Andersson

I will introduce, and give examples of, the notions of symplectic potential current, symplectic current, and Noether current for a Lagrangian field theory with local symmetries.
References:
Lee and... 

01.11.2016, 16:15 Uhr  –  Haus 9, Raum 0.14
Seminar Geometry and Physics

Lagrangian and Hamiltonian field theory

Florian Hanisch

We will briefly review some basic ideas of the Lagrangian and the Hamiltonian approach to classical field theory, including some examples. We will keep the talk at an elementary level (sometimes with... 

18.10.2016, 16:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Duistermaat-Heckmann-formula in finite dimensions

Florian Hanisch

The first session of the seminar will consist of 2 parts:

1) Discussion of the program for the semester.

2) Talk by F. Hanisch: Supersymmetry and the Duistermaat-Heckmann-formula in finite... 

30.06.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem

Matthias Ludewig, Florian Hanisch

The seminar will have two parts,

Matthias Ludewig: Finite dimensional approximation of path integrals (continuation).

Florian Hanisch: Supersymmetry and the Duistermaat-Heckman formula.


Witten's... 

23.06.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Discretisation of path integrals

Matthias Ludewig

We will describe different ways of discretising path integrals and compare different metrics on the (discrete) path space. Moreover, we will discuss different boundary conditions for path (fixed... 

09.06.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem

Florian Hanisch

This talk will focus on supergeodesics.

Witten's heuristic proof of the index theorem using supergeometry is well known but still not fully mathematically understood. We present the approaches to the... 

02.06.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem: Finite dimensional approximation

Lars Andersson

This talk will focus on finite dimensional approximations of path integrals.

Witten's heuristic proof of the index theorem using supergeometry is well known but still not fully mathematically... 

19.05.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem

Florian Hanisch, Matthias Ludewig

This is a continuation of the seminar on April 21 and 28.
Witten's heuristic proof of the index theorem using supergeometry is well known but still not fully mathematically understood. We present the... 

28.04.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem

Matthias Ludewig, Florian Hanisch

This is a continuation of the seminar on April 21.
Witten's heuristic proof of the index theorem using supergeometry is well known but still not fully mathematically understood. We present the... 

21.04.2016, 14:15 Uhr  –  Campus Golm, Haus 9, Raum 0.14
Seminar Geometry and Physics

Supersymmetry and the Atiyah-Singer Index Theorem

Matthias Ludewig, Florian Hanisch

Witten's heuristic proof of the index theorem using supergeometry is well known but still not fully mathematically understood. We present the approaches to the subject by Witten, Atiyah and Lott (and...