
The Guest Editors for this special issue are János Balog and
László Fehér
The present collection contains 21 papers by participants of the
O'Raifeartaigh Symposium on NonPerturbative and Symmetry Methods
in Field Theory,
held at Budapest, June 22−24, 2006. The symposium served
as a venue for an exchange of ideas on recent developments
in field theory and related subjects, and it also enhanced
the 'coherence' of a 'virtual community' of
researchers who had direct or indirect contact with
Lochlainn O'Raifeartaigh during their careers.
Indeed, about half of the 50 registered participants
were drawn from collaborators, among them several former postdoctoral
scholars at the Dublin Institute for Advanced Studies, and close colleagues of
Professor O'Raifeartaigh.
Together with the presence of two of his sons,
Conor and Cormac, this contributed especially to
a general warm feeling that dominated the meeting (the effective action of the
hot and humid weather on the participants was obviously negligible in comparison).
Being ourselves former postdocs of Lochlainn, we wish to believe
that he would have liked the meeting. The appreciation
of his eminent scientific contributions, and the lasting imprints made by
his outstandingly human, warm personality were apparent throughout
the conference.
As was made explicit in several talks,
many of us still miss him very much.
This is not the place to survey the work of Lochlainn O'Raifeartaigh (1933−2000),
a brief account can be found at the web page
maintained at Dublin Institute for Advanced Studies
http://www.stp.dias.ie/Lochlainn/lochlainn.html.
The best way to remember a scientist is to study his work.
Having this in mind, the list of publications
of Lochlainn O'Raifeartaigh is included
here
as a complement.
The slides of most of the 27 talks that were delivered in Budapest
(out of which 15 served as the basis of reports published in this collection),
and further auxiliary material can be viewed at the web page of the conference
http://www.kfki.hu/~lor2006,
which will be kept available for the coming years.
Budapest, December 7, 2006
The Guest Editors
Papers in this Issue:

Hidden Symmetries of Stochastic Models

Boyka Aneva
SIGMA 3 (2007), 068, 12 pages [ abs
pdf ps ]

Charges in Gauge Theories

David McMullan
SIGMA 3 (2007), 035, 8 pages [ abs
pdf ps ]

Quantum Deformations and Superintegrable Motions on Spaces with Variable Curvature

Orlando Ragnisco, Ángel Ballesteros, Francisco J. Herranz and Fabio Musso
SIGMA 3 (2007), 026, 20 pages [ abs
pdf ps ]

Lattice Field Theory with the Sign Problem and the Maximum Entropy Method

Masahiro Imachi, Yasuhiko Shinno and Hiroshi Yoneyama
SIGMA 3 (2007), 018, 7 pages [ abs
pdf ps ]

Boundary Liouville Theory: Hamiltonian Description and Quantization

Harald Dorn and George Jorjadze
SIGMA 3 (2007), 012, 18 pages [ abs
pdf ps ]

FiniteTemperature Form Factors: a Review

Benjamin Doyon
SIGMA 3 (2007), 011, 37 pages [ abs
pdf ps ]

Modular Symmetry and Fractional Charges in N = 2 Supersymmetric YangMills and the Quantum Hall Effect

Brian P. Dolan
SIGMA 3 (2007), 010, 31 pages [ abs
pdf ps ]

The Virasoro Algebra and Some Exceptional Lie and Finite Groups

Michael P. Tuite
SIGMA 3 (2007), 008, 13 pages [ abs
pdf ps ]

Generalized PottsModels and their Relevance for Gauge Theories

Andreas Wipf, Thomas Heinzl, Tobias Kaestner and Christian Wozar
SIGMA 3 (2007), 006, 14 pages [ abs
pdf ps ]

NonLocal FiniteSize Effects in the Dimer Model

Nickolay Sh. Izmailian, Vyatcheslav B. Priezzhev and Philippe Ruelle
SIGMA 3 (2007), 001, 12 pages [ abs
pdf ps ]

Noncommutative Geometry: Fuzzy Spaces, the GroenewoldMoyal Plane

Aiyalam P. Balachandran and Babar Ahmed Qureshi
SIGMA 2 (2006), 094, 9 pages [ abs
pdf ps ]

Dynamical R Matrices of Elliptic Quantum Groups and Connection Matrices for the qKZ Equations

Hitoshi Konno
SIGMA 2 (2006), 091, 25 pages [ abs
pdf ps ]

NonCommutative Mechanics in Mathematical & in Condensed Matter Physics

Peter A. Horváthy
SIGMA 2 (2006), 090, 9 pages [ abs
pdf ps ]

EinsteinRiemann Gravity on Deformed Spaces

Julius Wess
SIGMA 2 (2006), 089, 9 pages [ abs
pdf ps ]

ParaGrassmann Variables and Coherent States

Daniel C. Cabra, Enrique F. Moreno and Adrian Tanasă
SIGMA 2 (2006), 087, 8 pages [ abs
pdf ps ]

Quantum Gravity as a Broken Symmetry Phase of a BF Theory

Aleksandar Miković
SIGMA 2 (2006), 086, 5 pages [ abs
pdf ps ]

Fermion on Curved Spaces, Symmetries, and Quantum Anomalies

Mihai Visinescu
SIGMA 2 (2006), 083, 16 pages [ abs
pdf ps ]

The Form Factor Program: a Review and New Results − the Nested SU(N) OffShell Bethe Ansatz

Hratchya M. Babujian, Angela Foerster and Michael Karowski
SIGMA 2 (2006), 082, 16 pages [ abs
pdf ps ]

Quantum Field Theory in a NonCommutative Space: Theoretical Predictions and Numerical Results on the Fuzzy Sphere

Marco Panero
SIGMA 2 (2006), 081, 14 pages [ abs
pdf ps ]

uDeformed WZW Model and Its Gauging

Ctirad Klimčík
SIGMA 2 (2006), 079, 4 pages [ abs
pdf ps ]

On a Negative Flow of the AKNS Hierarchy and Its Relation to a TwoComponent CamassaHolm Equation

Henrik Aratyn, Jose Francisco Gomes and Abraham H. Zimerman
SIGMA 2 (2006), 070, 12 pages [ abs
pdf ps ]

