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Current interests.


General: I am interested in all kind of physics questions and I don't want to limit myself to certain topics. However, right now I am working on the following subjects.

  • analytic properties of Green's functions
  • quark-gluon vertex in the vacuum
  • color superconducting phases at high density
  • quark-gluon system at non-vanishing density

PostDoc: Currently I am working as a PostDoc at Washington University in St. Louis in the group of Mark Alford. We are interested in inhomogeneous color superconducting phases in the context of dense quark matter as relevant for neutron star physics.

PhD thesis: I did my PhD thesis under the supervision of Reinhard Alkofer at the Institute for Theoretical Physics, University of Graz, Austria. The main subject of the thesis was an investigation of the fully dressed quark-gluon vertex in the Landau gauge. This vertex is a central object of Quantum Chromo Dynamics and is needed as input for bound state equations, such as Bethe-Salpeter or Faddeev equations. We employed Dyson-Schwinger equations to study the coupled system of the quark propagator and the quark-gluon vertex, where for the latter we considered a truncation that has been derived from a 3PI effective action. Taking all eight transverse vertex structures into account, we found a stable solution of the fully back-coupled system that shows dynamical chiral symmetry breaking. In a subsequent analysis we isolated important tensor structures of the vertex and provided a solution of a reduced system that shows only small deviations from the full solution. The goal of the second project presented in the thesis was to compute the analytic structure of the non-perturbative quark propagator for arbitrary complex Euclidean momenta. Complex solutions of this propagator are needed for bound state equations. First, we developed the method and checked its validity perturbatively. Before we moved on to study the non-perturbative case, we employed our novel method to study scalar glueball operators at the Born level. We then extended our method such that it can be applied to non-perturbative studies. Finally, together with Mark Alford and Kai Schwenzer of Washington University in St. Louis, we studied strongly coupled flavor-asymmetric quark matter at intermediate densities as relevant for neutron star physics. We provided an estimate for the free energy of the Deformed Fermi Surface phase and discussed a possible instability of this phase. We furthermore investigated the possibility of four-fermion condensation at large flavor-asymmetry. We used a spin-1/2 toy model with two flavors and provided a setting based on exact renormalization group equations that is suitable to perform this analysis.

Diploma thesis: Ich did my Diploma thesis under the supervision of Reinhard Alkofer at the Institute for Theoretical Physics, University of Graz, Austria. Der Titel of the Diploma thesis is: "On the infrared behavior and analytic structure of Green functions in Yang-Mills theory".

  © 2014 · Andreas Windisch · E-Mailsend email