Eliezer Rabinovici

Duality in string background space

The (so-called) duality symmetry of closed strings with d compactified dimensions is reformulated in geometrical terms as an invariance under a particular Z2 transformation acting on (constant) metric, torsion and gauge background fields. Fixed points of this transformation - moded by SLd(Z) - yield enlarged symmetries based on simply-laced gauge groups. Exact duality requires revision of naive compactification prescriptions in the effective low-energy action. It could also prove important for dynamical compactification in string theories.

Superconformal quantum mechanics

N = 1 and N = 2 superconformal quantum mechanics are formulated and solved. Spontaneous symmetry breaking occurs. A de Sitter subalgebra is used to define new supersymmetric evolution operators. The modified system has a discrete spectrum exhibiting new supersymmetries. The N = 2 extended de Sitter superalgebra is spontaneously broken to N = 1. The relation to the behaviour of finite field theories and Poincare invariance is discussed.

Monte Carlo Study of Chiral Structure: The {Gross-Neveu} Model

Abstract The two-dimensional Gross-Neveu model is studied by Monte Carlo integration of Fermi fields. A clear transition is seen from a strong-coupling, massive, chiral symmetric phase to the weak-coupling chiral broken phase found in the continuum model. The weak-coupling behaviour of the dynamically generated scale agrees well with asymptotic freedom results.

On the short-distance structure of irrational non-commutative gauge theories

As shown by Hashimoto and Itzhaki in hep-th/9911057, the perturbative degrees of freedom of a non-commutative Yang-Mills theory (NCYM) on a torus are quasi-local only in a finite energy range. Outside that range one may resort to a Morita equivalent (or T-dual) description appropriate for that energy. In this note, we study NCYM on a non-commutative torus with an irrational deformation parameter θ. In that case, an infinite tower of dual descriptions is generically needed in order to describe the UV regime. We construct a hierarchy of dual descriptions in terms of the continued fraction approximations of θ. We encounter different descriptions depending on the level of the irrationality of θ and the amount of non-locality tolerated. The behavior turns out to be isomorphic to that found for the phase structure of the four-dimensional Villain N lattice gauge theories, which we revisit as a warm-up. At large t Hooft coupling, using the AdS/CFT correspondance, we find that there are domains of the radial coordinate U where no T-dual description makes the derivative expansion converge. The radial direction obtains multifractal characteristics near the boundary of AdS.

String theory : from gauge interactions to cosmology

Preface.- Lectures I. Beyond The Standard Models Of Particle Physics And Cosmology N. Arkhani-Hamed.- Strings In A Landscape T. Banks.- Quantization Of Holomorphic Forms And N = 1 Supersymmetry On Special Manifolds L. Baulieu.- Loewner Chains M. Bauer And D. Bernard.- Theory Of Cosmological Perturbations And Applications To Superstring Cosmology R.H. Brandenberger.- Towards A Topological G2 String J. De Boer et al.- Topological Strings, Matrix Models And Integrable Hierarchies R. Dijkgraaf.- On The ADS3 x S3 x S3 x S1 Background S. Elitzur.- Challenges Of Matrix Models A. Morozov.- Phenomenology Of Neutrino Oscillations L.B. Okun.- Topological Strings, Large N Duality, And Black Holes H. Ooguri.- Closed Strings In Misner Space: A Toy Model For A Big Bounce? B. Durin And B. Pioline.- Phenomenological Guide To Physics Beyond The Standard Model S. Pokorski.- Introduction To Cosmic F- And D-Strings J. Polchinski.- Long Time Scales And Eternal Black Holes J.L.F. Barbon And E. Rabinovici.- Semiclassical Strings And ADS/CFT A. Tseytlin.- II Seminars: Baryogenesis With Large Extra Dimensions K. Benakli.- Braneworld Cosmology Almost Without Branes G. Calcagni.- Chaotic Cascades For D-Branes On Singularities S. Franco et al.- N = 1 Gauge Theory Effective Superpotentials B. Gripaios.- Gromov-Witten Theory And Automorphic Forms D. Grunberg.- Black Hole Instabilities And Phase Transitions S. Hartnoll.- Probing Singularities V.E. Hubeny.- Inflation Unloaded M. Kleban.- D-Brane Effecive Actions P. Koerber.- ADS2 x S2 As An Exact Heterotic String Background D. Orlando.- Strings And D-Branes In Holographic Backgrounds D. Israel and A. Pakman.- Cosmic Censorship In ADS/CFT M. Rangamani.- Topics In Black Hole Production V.S.Rychkov.- Towards The Exact Dilatation Operator Of N= 4 Super Yang-Mills Theory A.V. Ryzhov.- Moduli Trapping And String Gas Cosmology S. Watson.- Stringy Geometry: Generalized Complex Structure M. Zabzine.- Integrability Of Superconformal Field Theory ANI SUSY N=1 KDV A.M. Zeitlin.- List Of Speakers.- List Of Participants.

D-BRANES IN THE BACKGROUND OF NS FIVEBRANES

We study the dynamics of D-branes in the near-horizon geometry of NS fivebranes. This leads to a holographically dual description of the physics of D-branes ending on and/or intersecting NS5-branes. We use it to verify some properties of such D-branes which were deduced indirectly in the past, and discuss some instabilities of non-supersymmetric brane configurations. Our construction also describes vacua of Little String Theory which are dual to open plus closed string theory in asymptotically linear dilaton spacetimes.

Induced boundary flow on the c = 1 orbifold moduli space

Boundary flow in the c = 1 2d CFT of a orbifold of a free boson on a circle is considered. Adding a bulk marginal operator to the c = 1 orbifold branch induces a boundary flow. We show that this flow is consistent for any bulk marginal operator and known initial given boundary condition. The supersymmetric case is also mentioned. For the circle branch of the moduli space, this has been shown by Fredenhagen et al (2007 J. Phys. A: Math. Theor. 40 F17). The ground state multiplicity (gb) is calculated and it is shown that it does indeed decrease.

Sowing the seeds of SESAME

Nestling under the shade of the olive groves at Al-Balqa Applied University in Jordan stands a unique project that began nearly a decade ago. It is special in that it has brought together Baharanian, Cypriot, Egyptian, Greek, Iranian, Israeli, Jordanian, Pakistani, Palestinian and Turkish scientists – all of whom are working towards a common goal of extending human knowledge.