# Renormalization Group Methods in Physics

## Bolyai Intensive Course

10-14 March, 2008

Organized jointly by the Institute For Theoretical Physics and Bolyai College

Supported by the National Office for Research and Technology (NKTH)

## Invited speakers

Ö. Legeza (Research Institute for Solid State Physics and Optics, Theoretical Solid State Physics Department)J. Polónyi ( Laboratoire de Physique Théorique, Univ. Strasbourg)

L. Sasvári (Department of Physics of Complex Systems, Eötvös University)

## The topics covered include:

- Brief survey of static and dynamic critical phenomena.
- Wilson's formulation of the renormalization group approach to static critical phenomena: basic characteristics of the flow, fixed points, linear and nonlinear scaling fields, scaling of physical observables, universality.
- Extension of the renormalization group approach to dynamic critical phenomena: renormalization of stochastic equations of motion, the role of conservation rules and Poisson brackets.
- Reaction-diffusion processes: basic phenomena, renormalization group analyses of anomalous kinetics.
- RG in particle physics. Running couplings, beta functions, asymptotic freedom. Resummation of leading logs. Renormalizability. Connection between high energy physics and statistical mechanics.
- Appelquiz-Carazzone decoupling theorem. Effective field theories.
- RG in field theory. Functional RG, Wegner-Houghton equation. RG for the effective action. Symmetry breaking. The global renormalization group.
- Fermions. Applications to solid state physics. Superconductivity.
- Renormalization of composite operators. The classical limit.
- Density matrix renormalization group (DMRG) and its relation to quantum information theory (QIT).
- Quantum information generation of the RG procedure. DMRG and quantum data compression.
- DMRG in real and in momentum space. Applications in solid state physics. Quantum phase transitions.
- Application of DMRG to quantum chemistry. Molecular orbitals and QIT. Determination of spectra of excitations. The dynamically extended active space (DEAS) approach.
- Application of DMRG to dynamical and time-dependent phenomena. Extension to finite temperature and two-dimensions.

## Lecture notes

J. Polónyi: pdf1 pdf2Ö. Legeza: pdf1 pdf2 pdf3 pdf4 pdf5 pdf6 pdf7 pdf8 ps1

## Timetable

**Opening**: Monday, 8:45-9:00

Monday | Tuesday | Wednesday | Thursday | Friday | |

9:00-9:50 | L. Sasvári | J. Polónyi | Ö. Legeza | J. Polónyi | Ö. Legeza |

9:50-10:10 | Coffee break | ||||

10:10-11:00 | L. Sasvári | J. Polónyi | Ö. Legeza | Ö. Legeza | Ö. Legeza |

11:10-12:00 | J. Polónyi | L. Sasvári | S. Nagy |
M. Nemevsek |
G. Zaránd |

12:00-14:00 | Lunch break | ||||

14:00-14:50 | J. Polónyi | J. Polónyi | J. Polónyi | L. Sasvári | Ö. Legeza |

15:00-15:50 | J. Polónyi | L. Sasvári | L. Sasvári | Ö. Legeza | J. Polónyi |

15:50-16:10 | Coffee break | ||||

16:10-17:00 | I. Nándori |
L. Sasvári | L. Sasvári | Ö. Legeza | J. Polónyi |

17:10-18:00 | Discussion | ||||

Talks indicated in italic are 30 minutes long, all others take 50 minutes.

The program includes an invited talk:

G. Zaránd (University of Technology, Budapest): Kondo effect (preliminary title)

Short talks by the participants (30 mins, see abstracts):

S. Nagy: Renormalization of periodic models

I. Nándori: Renormalization of the multi-layer sine-Gordon model

M. Nemevsek: Gauge coupling unification in a minimal extension of SU(5)

## Location

Bolyai College (H-1117 Budapest, Nándorfejérvári út 13.)

## Registered participants

Name | Affiliation |

D. Ábel | Eötvös University, Budapest |

G. Barcza | Eötvös University, Budapest |

Z. Bajnok | Eötvös University, Budapest |

F. Csikor | Eötvös University, Budapest |

G. Cynolter | Eötvös University, Budapest |

O. El Deeb | Eötvös University, Budapest |

G. Endrődi | Eötvös University, Budapest |

G. Fejős | Eötvös University, Budapest |

P.D. Ispánovity | Eötvös University, Budapest |

Á. Kardos | University of Debrecen |

N. Kosnik | Jozef Stefan Institute, Ljubljana |

I. Kovács | Eötvös University, Budapest |

J.I. Márfy | Eötvös University, Budapest |

E. Mátyus | Eötvös University, Budapest |

M. Nagy | Eötvös University, Budapest |

S. Nagy | University of Debrecen |

I. Nándori | Inst. Nucl. Res., Debrecen |

M. Nemevsek | Jozef Stefan Institute, Ljubljana |

V. Pangon | University of Strasbourg |

M. Planat | University of Strasbourg |

B. Pozsgay | Eötvös University, Budapest |

Á. Rapp | University of Technology, Budapest |

M. Rontó | Eötvös University, Budapest |

Zs. Simon | Eötvös University, Budapest |

Á. Szabados | Eötvös University, Budapest |

M. Szőts | Eötvös University, Budapest |

A. Suchecka | University of Strasbourg |

A. Trombettoni | SISSA, Trieste |

## Application

Applications can be made by e-mail to G. Takács (see address below).

### Deadline: 15th February 2008.

Please send contact details (name and address of institution, phone, e-mail), position (also name and contact details of supervisor for graduate students) and a brief statement of interest (including summary of present research subject and the reason of why you wish to attend).

There is shared accomodation for a few (3-5) persons available at the College site. Those who wish to book one of them must apply no later than the 18th of January, 2008.

The course is going to be registered with the University's Doctoral School of Physics (6 credits), and also as an intensive special course for 5th year physics students (2 credits).

## Scientific organizer and contact person

G. Takács (Institute for Theoretical Physics)E-mail: takacs(at)elte.hu

P. Surján (Bolyai College, director) G. Takács (Institute for Theoretical Physics, scientific organizer)