Theorie-Palaver

Informal parley on any interesting topic in physics

Organizer: Jean-Sebastien Gagnon
Date: Mondays, 13:00
Room: S2|11 207

This informal gathering is organized by students for students (with the help of postdocs and professors). The goal of each gathering is to discuss physics topics of interest to the attendees, ranging from classic or recent papers to their own research projects. The planned format of each meeting is that a designated person prepares a 15-25 minutes blackboard talk in order to spark off some discussions (which should hopefully last until our alloted one hour time slot is spent).

Past Seminars

14. 08. 2014 at 16:00
S2 11/10

Theorie-Palaver

Dominik Smith (TU Darmstadt)
Lattice simulations of graphene

The goal of the seminar is to present the motivation for lattice field theorists and high-energy physicists to study graphene, then present a step-by-step derivation of the theoretical basis of Hybrid-Monte-Carlo simulations of graphene and then give an overview over results obtained.

24. 10. 2011 at 13:00
S2 11/207

Theorie-Palaver

Hans-Peter Pavel (TU Darmstadt and JINR Dubna)
Calculation of the spin-0 glueball spectrum

As an illustrative example the simplest case of a spin-0 glueball spectrum of SU(2) Yang-Mills quantum mechanics is calculated with high precision, using the analytical solutions of the corresponding 3-dim harmonic oscillator Schroedinger equation (a Calegero-type model) as appropriate basis states.

17. 10. 2011 at 13:00
S2 11/207

Theorie-Palaver

Hans-Peter Pavel (TU Darmstadt and JINR Dubna)
Hamiltonian formulation of gauge theories

An introduction to the Hamiltonian formulation of gauge theories
on the classical and the quantum level is given. It allows for
the description of gauge theories in terms of physical degrees of freedom
and the application of the powerful variational method.

06. 07. 2011 at 13:00
S2 11/207

Theorie-Palaver

Dr Jean-Sebastien Gagnon (TU Darmstadt)
Accelerated Expansion and the Dark Energy Problem

In this Palaver I present a brief (non exhaustive) review of the dark energy problem. Starting from observational evidences for an accelerated universal expansion, I go on with the simplest solution to this problem (i.e. adding a cosmological constant to Einstein's equations) and show its ``unnaturalness''. If time permits, I will present some other ideas/models that have been proposed to explain this phenomenon (e.g. quintessence, braneworlds, voids).

20. 06. 2011 at 13:00
S2 11/207

Theorie-Palaver

Daniel Nowakowski (TU Darmstadt)
Music concerts, card tricks, and the shutdown of the LHC; or How the Higgs suppresses its appearance

In this talk I give a short introduction about the model of complex action by M. Ninomiya and H.B. Nielsen. Especially I focus on possible effects on the running of the Large Hadron Collider. Also an experiment, which would allow to test the fate of LHC with a card game, will be presented. Possible effects of the complex action model would be, that the Higgs suppresses its production by backward causation, e.g. in collider experiments. Therefore the appearance of many Higgs-particles in certain experiments would possess strong influence of the correctness of this theory. It is argued, that the accident of the LHC shortly after start was such a signal of suppression and that the cancelation of the Superconducting Super-Collider (SSC) was due to backward causation. In my palaver I will review critically the statements of Nielsen et al. for this model, point out further implications of complex actions and try to estimate, which future collider experiment is "allowed by the Higgs", if the model is true. If there is some time left, I wish to point out how the complex action model is related to EPS-Bell's Theorem problem.

23. 05. 2011 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
Bell's inequalities and locality

In my talk, I will present some general ideas linking quantum and classical correlation. I will briefly talk about quantum entanglement and what seperates local theories as a class from QM. Also, i wish to point out experimental problems with detection efficiency and i will present a very easy model that abuses non-perfect detectors to reproduce quantum mechanical expectation values exactly while beeing local with the help of hidden variables.

09. 05. 2011 at 13:00
S2 11/207

Theorie-Palaver

Nico Formanek (TU Darmstadt)
Quantum Logic

I will talk about the basic concepts in quantum logic (e.g. some lattice theory) and how they relate to the algebraic concept of Hilbert spaces which are normally taught in physics. From a more philosophical point of view I hope to shed some light on how quantum logic might or might not illuminate some problems (hidden variables and the likes) which "haunt" the interpretations of quantum mechanics.

28. 03. 2011 at 13:00
S2 11/207

Theorie-Palaver

Sam Edwards (TU Darmstadt)
Can gravitons be detected?

A few years ago, Freeman Dyson asked the question if it is possible to detect a single graviton in a realistic experimental setting. The answer to this question is linked to the relevance of quantizing gravity. In this Palaver, I will present a paper (arXiv: gr-qc/0601043) that discusses the possibility of detecting a single graviton. I intend to present the salient points of the paper, but leave plenty of room for (fiery) discussions. Please read the paper and be prepared!

14. 03. 2011 at 13:00
S2 14/401

Theorie-Palaver

David Mesterhazy (TU Darmstadt)
Three-dimensional gravity

I will be discussing some aspects related to gravity in three dimensions. We will see why it is an interesting model to look at and on the way, a few surprises will appear.

21. 02. 2011 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
Quantum versus classical statistical dynamics

The non-equlibrium dynamics of quantum fields is relevant for a variety of physical problems. In general this requires non-perturbative techniques as to secular divergences arising in a perturbative treatment.
In the past decades classical statistical field theories were discovered to provide an approximate description of the quantum dynamics .
The applications range from early universe cosmology, via ultra cold Bose gases to high energy nuclear ion collisions. The commons and differences of quantum and classical statistical dynamics will be explored from first principles. The classical statistical approximation will be compared to other common approximation schemes.

07. 02. 2011 at 13:00
S2 14/401

Theorie-Palaver

Piotr Piasecki (TU Darmstadt)
Functional Renormalization Group

Today I will give a short introduction to the functional Renormalization Group. I will explain its basic concepts and will derive the famous Wetterich Equation. After that this Equation will be applied to a simple example.

24. 01. 2011 at 13:00
S2 14/401

Theorie-Palaver

Dr Jean-Sebastien Gagnon (TU Darmstadt)
Baryogenesis and the Standard Model

In this Palaver I will present some fundamental concepts of baryogenesis. Starting with a brief review of observational evidences for an asymmetric universe, I will go through the necessary conditions a model must have in order to produce a baryon asymmetry (Sakharov conditions) and show if the Standard Model has "what it takes"' to explain it.

13. 12. 2010 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
The Higgs - in the GWS theory/SM and a little bit beyond

I will start with the Higgs mechanism and the Higgs boson in the electroweak sector of the standard model. There the (rather aesthetic) fine-tuning problem occurs, which has become a reason for theorists to consider theories beyond the current standard model. I will therefore try to sketch the ideas concerning the Higgs boson in technicolour and supersymmetry.

29. 11. 2010 at 13:00
S2 14/401

Theorie-Palaver

Hannes Basler (TU Darmstadt)
Some aspects of color superconductivity

Starting with a sketch of the Proof of Existence of Color Superconductivity, I will discuss the most symmetric pairing pattern in three-flavor quark matter, the color-flavor locked (CFL) phase, also showing how stress on CFL pairs leads to less symmetric pairing patterns. After these general consideration I will give an short overview of the different approaches to describe color superconductivity, for some reason focusing on the NJL model.

01. 11. 2010 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
Introduction to the Two-Particle Irreducible Effective Action, Part 2

After having introduced the 2PI effective action in the first part of this introduction, I will explain why it is so well suited for nonequilibrium QFT. Special emphasis will be placed on the implementation of the statistical aspects of nonequilibrium physics and the differences to vacuum and thermal QFT. The aim is then to derive the evolution equations of certain propagators which contain important information about the nonequilibrium evolution of a given system.

18. 10. 2010 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
A Potpourri of Geometrical Quantization Concepts

The topic will be centered around the following key words: Geometrical quantization, quantization of the Riemann sphere as an example, spinor geometry, Hopf fibration and monopole harmonics.

04. 10. 2010 at 13:00
S2 14/401

Theorie-Palaver

(TU Darmstadt)
Introduction to DSE Phenomenology; the Muon g-2

I will give a brief introduction to phenomenological aspects of Dyson-Schwinger Equations and will concentrate on the application of that approach to hadronic contributions to the g-2 of the muon.

20. 09. 2010 at 13:00
S2 14/401

Theorie-Palaver

Nils Strodthoff (TU Darmstadt)
Introduction to Anomalies

I will give a brief introduction to anomalies in quantum field theory. As an example I will consider the chiral anomaly. I want to show that anomalies are not just a theoretical peculiarity but on the one hand have direct experimental consequences and on the other hand impose strong constraints on gauge theories via the requirement of anomaly cancellation.

13. 09. 2010 at 13:00
S2 14/401

Theorie-Palaver

Stefano Carignano (TU Darmstadt)
On Heavy Quarks in the Quark-Gluon Plasma

Why are heavy quark observables so interesting in the heavy ion business? How can we extract some information on the properties of the Quark-Gluon plasma from them? What have we discovered so far? This, and much more, after a short commercial break.

Address

Technische Universität Darmstadt

Institut für Kernphysik
Theoriezentrum

S2|11
Schlossgartenstraße 2
64289 Darmstadt

Secretary

Genette Kluckner

+49 6151 16 21551
+49 6151 16 21555

Stephanie Müller

+49 6151 16 21558
+49 6151 16 21555

Next Seminar

Theorie-Seminar

on 28. 05. 2019 at 13:15
(S2 11/207)
Dietrich Roscher
Fractionalization in spin systems: an FRG perspective
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