Lattice Gauge Theory group

GPU 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 an NVIDIA GPU 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 and were funded by various funding agencies for which we are grateful, these include the Lendulet grant of the Hungarian Academy of Sciences, the OTKA-NF-104034 grant of OTKA and 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 ELFT seminars at the Department of Theoretical Physics

Location: 2nd floor, 2.54, Novobatzky room, 1117 Budapest, Pazmany Peter setany 1/a

Time: Wednesdays at 14:15

See the archive for seminars in past years.


  • 4 September 2019, Marton Lajer (Wigner-ELTE)

    Truncated Spectrum Approach to the sinh-Gordon model and its generalizations

    We consider a class of models obtained by perturbing the non-compact Gaussian CFT with two vertex operators. These include the integrable sinh-Gordon and Bullough-Dodd models as special cases. The above theories are special as they can be considered equivalently as perturbations of Liouville CFTs, and the consistency between these viewpoints leads to interesting properties. We apply the Truncated Spectrum Approach (TSA) to these models. Despite apparent problems regarding the perturbative RG improvement, we argue that TSA is applicable as long as both related Liouville models are below the self-dual point. We check that the small-volume asymptotics of the spectrum is described by a quantization condition involving the Liouville reflection amplitude even in the non-integrable case. It has long been known that the reflection amplitude also appears in a set of functional equations describing the VEVs of vertex operators. The analytic ?minimal? solution thereof is numerically confirmed to provide the exact expectation values in both integrable subsets. We find that the similar ?minimal? solution with respect to the general, non-integrable models still provides a good approximation over a wide range of parameter space (even though it is not exact). In the case of VEVs, TSA always breaks down just before reaching the first zeroes of the minimal solution, which coincide with the Seiberg bounds of the related Liouville theories.

  • 18 September 2019, Miguel Tierz (Universidade de Lisboa)

    Matrix models and Chern-Simons theory slides

    We first give an introduction to the basics of random matrix theory, with an emphasis on its relevance in gauge theory. We then focus on the description, in terms of matrix models, of Chern-Simons theories, including the case of theories with supersymmetric matter.

  • 2 October 2019, Gabor Etesi (BME)

    The four dimensional Yang--Mills partition function in the vicinity of the vacuum

    In this lecture we outline the computation of the partition function of four dimensional Euclidean, non-supersymmetric SU(2) Yang--Mills theory in the perturbative and weak coupling regime i.e. in a small open ball about the flat connection (what we call the "vicinity of the vacuum") and when the gauge coupling constant acquires a small but finite value.

    The computation is based on various known inequalities, valid only in four dimensions, providing two-sided estimates for the exponentiated Yang--Mills action in terms of the L^2-norm of the derivative of the gauge potential only; these estimates then give rise to Gaussian-like infinite dimensional integrals involving the Laplacian hence can be formally computed via zeta-function and heat kernel techniques. It then turns out that these integrals give a sharp value for the partition function in the aforementioned perturbative and weak coupling regime of the theory.

    A physical interpretation of the resulting closed formula in the realm of asymptotic freedom is also exhibited.

    More details: 1907.05669 [hep-th]

  • 9 October 2019, Gergely Fejos (Eotvos)

    Axial anomaly and hadronic properties in a nuclear medium slides

    I will show recent results on meson and nucleon dynamics at finite baryon density and temperature, by coupling the nucleon field and the omega meson to the three flavor linear sigma model. Using the functional renormalization group (FRG) method, I will show how to calculate hadronic properties at the nuclear liquid-gas transition, and argue that mesonic fluctuations increase the strength of the coefficient of the U_A(1) breaking determinant operator. Density dependence of the meson masses and partial restoration of chiral symmetry will also be discussed.

  • 16 October 2019, Janos Balog (Wigner)

    Non-linear sigma model and the Maxwell-Kirchhoff electrostatic problem slides

    Three different physical systems: the O(N) nonlinear sigma model and the Lieb-Liniger model in 1 dimension, and the parallel disks capacitor, are all described by (nearly) the same TBA-type integral equation. Sigma model perturbation theory, which is completely solved, provides solutions for the two other systems as well. The disk capacitor problem has historical interest, mainly because in the past many famous physicists took up the challenge of solving it.

  • 30 October 2019, Ralf Ulrich (Karlsruhe)

    Importance of dedicated LHC measurements for cosmic ray physics

    When ultra-high energy particles from astrophysical objects arrive at earth they cannot be detected directly. They interact with the atmosphere and produce huge extensive air shower cascades. Such cascades can be experimentally observed easily and are our only handle to study the universe at the highest energies. By their nature, air showers fundamentally connect particle physics and astrophysics together. The microscopic processes in the air showers must be understood precisely to make best use of the recorded data. The LHC plays a crucial role in studying such processes in detail.

  • 6 November 2019, Timo Karkkainen (Eotvos)

    TBA

    TBA

  • 13 November 2019, Josu Hernandez (Eotvos)

    TBA

    TBA

  • 20 November 2019, Carlos Pena (Universidad Autonoma Madrid)

    TBA

    TBA

  • 27 November 2019, Michael Trott (University of Copenhagen)

    TBA

    TBA

  • 4 December 2019

    No seminar, Zimanyi Winter School and Workshop

  • 11 December 2019, Robert Vertesi (Wigner)

    TBA

    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

Matteo Giordano

assistant professor

2009 PhD - University of Pisa, Italy

2010-2010 postdoc - IPhT/CEA-Saclay, France

2010-2012 postdoc - University of Zaragoza, Spain

2012-2015 postdoc - ATOMKI, Debrecen, Hungary

2015-2018 postdoc - Eotvos University, Budapest, Hungary

Kornel Kapas

PhD student

2018- Eotvos University, Hungary

 

 

 

 

 

 

 

 

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

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

 

 

Attila Pasztor

postdoc

2015 PhD - Eotvos University, Hungary

2016-2018 postdoc - Wuppertal University, Germany

2018- postdoc - Eotvos University, Hungary

Lorinc Szikszai

PhD student

2016- Eotvos University, Hungary

 

 

 

 

Zoltan Varga

PhD student

2018- Eotvos University, Hungary

 

 

Former members

Gergely Endrodi

2009 PhD - Eotvos University, Hungary

2010-2015 postdoc - University of Regensburg, Germany

2016- Emmy Noether group leader - University of Frankfurt, Germany

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

Santanu Mondal

2013 PhD - University of Calcutta, India

2013-2016 postdoc - Eotvos University, Hungary

2016- postdoc - National Chiao Tung University, Taiwan

Ferenc Pittler

2013 PhD - University of Pecs, Hungary

2013-2016 postdoc - Eotvos University, Budapest

2017- postdoc - Bonn University, Germany

Andras Saradi

2014 MSc - Eotvos University, Hungary

 

 

 

 

 

 

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

 

 

Csaba Torok

2017 PhD - Eotvos University, Hungary

2017- postdoc - Wuppertal University, Germany

 

Norbert Trombitas

PhD student

2015 PhD - Eotvos University, Hungary

 

 

Publications

Since it is tricky to locate all papers by a large number of people whose names are not unique on inspire, you can try various search queries:

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.



For visitors

Our department is on the Buda side of the Danube very close to the Petofi Bridge:

The Department of Theoretical Physics is on the first floor on the Danube facing side of the building: