Lattice Gauge Theory group

CUDA Research Center We are the lattice gauge theory group at the Eotvos University in Budapest, part of the Department of Theoretical Physics at the Faculty of Science. Since 2011 we are a CUDA Research Center.

Currently there are nine members and we are seeking new ones. Positions are available for PhD students and postdocs for 2 - 4 years appointments. If you are interested please email Sandor Katz at katz {at} bodri {dot} elte {dot} hu or Daniel Nogradi at nogradi {at} bodri {dot} elte {dot} hu.

Our activities are funded by the Lendulet grant of the Hungarian Academy of Sciences and by the OTKA-NF-104034 grant of OTKA.

We are also grateful to our past funding agencies, the EU Framework Programme 7 grant (FP7/2007-2013)/ERC No 208740.

Research

Our primary interests are:

  • Chiral symmetry restoration and deconfinement in QCD with Wilson fermions
  • Finite chemical potential
  • QCD hadron spectrum
  • Eigenvalue distributions of the overlap Dirac operator
  • Strongly interacting Higgs sector - strong dynamics
  • Conformal gauge theories

Seminar

Weekly seminars of the Department of Theoretical Physics

Location: 2nd floor, 2.54, Novobatzky room

Time: Wednesdays at 14:15


  • 10 September 2014, Mate Lencses (Eotvos University, Hungary)

    Excited state TBA and renormalized TCSA in the scaling Potts model

    We consider the field theory describing the scaling limit of the Potts quantum spin chain using a combination of two approaches. The first is the renormalized truncated conformal space approach (TCSA), while the second one is a new thermodynamic Bethe Ansatz (TBA) system for the excited state spectrum in finite volume. For the TCSA we investigate and clarify several aspects of the renormalization procedure and counter term construction. The TBA system is first verified by comparing its ultraviolet limit to conformal field theory and the infrared limit to exact S-matrix predictions. We then show that the TBA and the renormalized TCSA match each other to a very high precision for a large range of the volume parameter, providing both a further verification of the TBA system and a demonstration of the efficiency of the TCSA renormalization procedure. We also discuss the lessons learned from our results concerning recent developments regarding the low-energy scattering of quasi-particles in the quantum Potts spin chain. See arXiv:1405.3157

  • 17 September 2014, Marton Kormos (BME, Hungary)

    Correlations after quantum quenches in the XXZ spin chain: Failure of the Generalized Gibbs Ensemble

    The topic of thermalization of isolated quantum systems has enjoyed a lot of attention lately, partially due to the fast evolving experimental techniques in cold atom systems. Until recently, it was generally accepted that even completely isolated many-body systems self-thermalize to a certain extent: their evolution from a non-equilibrium initial state leads to a local thermal equilibrium (Gibbs ensemble) or to the Generalized Gibbs Ensemble (GGE) for integrable systems that have extra conserved quantities. We studied the non-equilibrium time evolution of the integrable spin-1/2 anisotropic Heisenberg (XXZ) spin chain, and we found that various short-ranged spin correlators in the long-time limit deviate significantly from predictions based on the GGE hypothesis. By computing the asymptotic spin correlators within the recently proposed quench action formalism, however, we find excellent agreement with the numerical data. We therefore conclude that the GGE cannot give a complete description even of local observables. This surprising result reopens the quest for the correct statistical description of the equilibrium state of integrable systems.

  • 24 September 2014, Attila Pasztor (Eotvos University, Hungary)

    Heavy quarkonium at finite temperature from 2+1 flavour lattice QCD

    Heavy quarkonium states are of great interest as a possible thermometer of hot QCD matter. For this idea to work, the determination of the dissociation temperatures of the different states is necessary. In this talk I will review some recent results from lattice QCD with 2+1 dynamical quarks that gives input to this long-standing problem. In the first part of the talk I will discuss the direct Maximum Entropy determination of spectral functions and to how much extent the lattice data depend on the heavy quark diffusion coefficient. In the the second part I will present continuum results on the static quark-antiquark pair free energies and the electric and magnetic screening masses in the QGP.

  • 1 October 2014, Guido Franchetti (Heriot-Watt University, UK)

    Geometric models of matter

    Geometric models of matter is a framework introduced by Atiyah, Manton and Schroers with the aim of modelling particles by means of 4-dimensional Riemannian manifolds. In this talk I will review the original proposal as well as more recent work about ALF gravitational instantons as models for multi-particle systems. Harmonic forms on these spaces have interesting properties which will be also discussed.

  • 15 October 2014, Istvan Nandori (ATOMKI, Hungary)

    TBA

  • 22 October 2014, Gabor Somogyi (CERN, Switzerland)

    TBA

  • 29 October 2014, Janos Polonyi (University of Strasbourg, France)

    TBA

  • 5 November 2014, Zoltan Bajnok (Wigner Center, Hungary)

    TBA

  • 12 November 2014, Gergely Marko (Eotvos University, Hungary)

    TBA

  • 19 November 2014, Gabor Etesi (BME, Hungary)

    TBA

  • 26 November 2014, Janos Balog (Wigner Center, Hungary)

    TBA

For students

Our group offers TDK, diploma and PhD topics in Lattice Field Theory.

Please contact Sandor: katz {at} bodri {dot} elte {dot} hu
or Daniel: nogradi {at} bodri {dot} elte {dot} hu
in case you are interested.

Current topics include:

  • QCD thermodynamics
  • SU(N) gauge theory with topological lattice action
  • O(3) non-linear sigma model with topological term
  • Beyond Standard Model - technicolor

People

Sandor Katz

professor

2001 PhD - Eotvos University, Hungary

2001-2003 postdoc - DESY, Hamburg, Germany

2003-2005 postdoc - University of Wuppertal, Germany

2006-2012 assistant professor - Eotvos University, Hungary

2012- professor - Eotvos University, Hungary

katz {at} bodri {dot} elte {dot} hu

Santanu Mondal

postdoc

2013 PhD - University of Calcutta, India

2013 postdoc - Eotvos University, Hungary

santanu {at} bodri {dot} elte {dot} hu

 

 

 

 

 

 

Daniel Nogradi

assistant professor

2005 PhD - University of Leiden, the Netherlands

2005-2007 postdoc - University of Wuppertal, Germany

2007-2009 postdoc - UCSD, USA

2009-2011 senior research fellow - Eotvos University, Budapest

2011 assistant professor - Eotvos University, Budapest

nogradi {at} bodri {dot} elte {dot} hu

Attila Pasztor

PhD student

2010 - Eotvos University, Hungary

apasztor {at} bodri {dot} elte {dot} hu

 

 

 

 

 

 

 

Ferenc Pittler

postdoc

2013 PhD - University of Pecs, Hungary

2013- postdoc - Eotvos University, Budapest

pittler {at} bodri {dot} elte {dot} hu

 

Andras Saradi

MSc student

2014 - Eotvos University, Hungary

 

 

 

 

 

 

Csaba Torok

MSc student

2014 - Eotvos University, Hungary

 

Norbert Trombitas

PhD student

2010 - Eotvos University, Hungary

trombitas {at} ludens {dot} elte {dot} hu

 

 

Lorinc Szikszai

BSc student

2014 - Eotvos University, Hungary

 

 

Former members

Gergely Endrodi

2009 PhD - Eotvos University, Hungary

2010 postdoc - University of Regensburg, Germany

endrodi {at} general {dot} elte {dot} hu

Tamas Kovacs

1996 PhD - UCLA, USA

1996-1998 postdoc - University of Colorado, Boulder, USA

1998-2000 postdoc - University of Leiden, the Netherlands

2000-2002 postdoc - DESY, Zeuthen, Germany

2002-2011 professor - University of Pecs, Hungary

2011- senior researcher - ATOMKI, Debrecen, Hungary

kgt {at} fizika {dot} ttk {dot} pte {dot} hu

Balint Toth

2005-2006 research assistant - University of Wuppertal, Germany

2007 assistant lecturer - University of Pecs, Hungary

2010 PhD - Eotvos University, Hungary

2010 postdoc - University of Wuppertal, Germany

tothbalint {at} szofi {dot} elte {dot} hu

 

 

Recent papers

Computing

Our group has access to a number of high performance computer installations in Europe and also maintains several PC and GPU clusters on site in Budapest.

Our primary resource is a 128 node cluster with two NVIDIA GTX 275 cards in each node, hosted in Budapest. There is also a 60 node cluster with one NVIDIA GTX 8800 card per node.

In addition we also have access to the Juropa cluster and the BlueGene/P installation in Forschungszentrum Juelich, Germany.

Our collaboriation with the University of Wuppertal, Germany also allows us to use several PC and GPU clusters there.



In case you are interested you can see a map of GPU cluster installations throughout the world dedicated to Lattice Gauge Theory.

For visitors

You will most likely stay at the Peregrinus hotel in the downtown area of Pest.

The simplest way to get to/from your hotel from/to the airport is by taxi. Ask for the fixed rate which should be around 20-22 euros.

Our department is on the Buda side of the Danube very close to the Petofi Bridge and it is about a 30-35 minutes walk from the hotel:


View Larger Map

You exit your hotel, walk past the Great Market Hall (definitely worth a closer look if you have about half an hour or an hour!) and the Corvinus University, cross the Danube on the Szabadsag Bridge and walk South. You will pass the Budapest University of Technology and the Petofi Bridge and our building will be a redish seven-story building on the right. The Department of Theoretical Physics is on the first floor on the Danube facing side of the building: