Shimon Yankielowicz - Profile on Academia.edu (original) (raw)

Papers by Shimon Yankielowicz

Journal of High Energy Physics, Mar 7, 2001

We look at the string theory dual of the N = 1 * theory, involving 5-branes, which was recently p... more We look at the string theory dual of the N = 1 * theory, involving 5-branes, which was recently proposed by Polchinski and Strassler [1]. We argue that SUGRA alone is not enough in order to obtain the correct screening and confinement behaviour of the various massive field theory vacua, but that appropriate worldvolume phenomena of the 5-branes must be included. We therefore work within the SUGRA approximation, also taking into account the brane dynamics, and classify all the SUGRA configurations. In this level of analysis, we find multiple valid configurations for every given vacuum. We discuss some possible resolutions of this perplexing result. We also consider the spectrum of asymptotic states, and discuss the global symmetries of the SUGRA solution of the N = 1 * theory and of the N = 0 * theory obtained from it by explicit supersymmetry breaking.

arXiv (Cornell University), Sep 7, 2022

We construct the Faddeev-Kulish dressed multiparticle states of electrically and magnetically cha... more We construct the Faddeev-Kulish dressed multiparticle states of electrically and magnetically charged particles, incorporating the effects of real and virtual soft photons. We calculate the properties of such dressed states under Lorentz transformations, and find that they can be identified with the pairwise multi-particle states that transform under the pairwise little group. The shifts in the dressing factors under Lorentz transformations are finite and have a simple geometric interpretation. Using the transformation properties of the dressed states we also present a novel, fully quantum field theoretic derivation of the geometric (Berry) phase obtained by an adiabatic rotation of the Dirac string, and also of the Dirac quantization condition. For half integer pairwise helcity, we show that these multiparticle states have flipped spin-statistics, reproducing the surprising fact that fermions can be made out of bosons.

Nonperturbative Approach to Quantum Field Theories: Phase Transitions and Confinement

Lectures given at, Aug 1, 1976

Physics Letters B, Jun 1, 1984

Scaling Laws and Equal - Time Commutators

Physical review, Mar 15, 1973

... VOLUME 7, NUMBER 6 Scaling Laws and Equal-Time Commutators Yitzhak Frishman and Shimon Yankie... more ... VOLUME 7, NUMBER 6 Scaling Laws and Equal-Time Commutators Yitzhak Frishman and Shimon Yankielowicz Department of Nuclear Physics, Weizmann ... This point is worth stressing because our free-field operator is completely different from the Carniglia-Mandel free-field ...

Physics Letters B, Jun 1, 1982

Physical review, Apr 15, 1996

We employ an algebraic approach for unifying perturbative and non-perturbative superstring states... more We employ an algebraic approach for unifying perturbative and non-perturbative superstring states on an equal footing, in the form of U-duality multiplets, at all excited string levels. In compactified type-IIA supertring theory we present evidence that the multiplet is labelled by two spaces, "index" space and "base" space, on which U acts without mixing them. Both spaces are non-perturbative extensions of similar spaces that label perturbative T-duality multiplets. Base space consists of all the central charges of the 11D SUSY algebra, while index space corresponds to represetations of the maximal compact subgroup K ⊂ U. This structure predicts the quantum numbers of the non-perturbative states. We also discuss whether and how U-multiplets may coexist with 11dimensional multiplets, that are associated with an additional non-perturbative 11D structure that seems to be lurking behind in the underlying theory.

Physics Letters B, Oct 1, 1983

Non-integer charges on topological objects in the presence of fermions are further investagated. ... more Non-integer charges on topological objects in the presence of fermions are further investagated. The connection with anomalous commutators is discussed. The reason for the identical results m two dimensional sohtons and four dimensional monopoles is pointed out.

Physical review, Dec 30, 2020

Nuclear Physics B, Sep 1, 1995

Journal of High Energy Physics, Dec 1, 2017

Using the well-known low-energy effective Lagrangian of QCD-valid for small (non-vanishing) quark... more Using the well-known low-energy effective Lagrangian of QCD-valid for small (non-vanishing) quark masses and a large number of colors-we study in detail the regions of parameter space where CP is spontaneously broken/unbroken for a vacuum angle θ = π. In the CP broken region there are first order phase transitions as one crosses θ = π, while on the (hyper)surface separating the two regions, there are second order phase transitions signalled by the vanishing of the mass of a pseudo Nambu-Goldstone boson and by a divergent QCD topological susceptibility. The second order point sits at the end of a first order line associated with the CP spontaneous breaking, in the appropriate complex parameter plane. When the effective Lagrangian is extended by the inclusion of an axion these features of QCD imply that standard calculations of the axion potential have to be revised if the QCD parameters fall in the above mentioned CP broken region, in spite of the fact that the axion solves the strong-CP problem. These last results could be of interest for axionic dark matter calculations if the topological susceptibility of pure Yang-Mills theory falls off sufficiently fast when temperature is increased towards the QCD deconfining transition.

Nuclear Physics B, Feb 1, 1999

We study the free energy of N = 4 super Yang-Mills theory in the Higgs phase with a mass scale M ... more We study the free energy of N = 4 super Yang-Mills theory in the Higgs phase with a mass scale M corresponding to non-zero v.e.v. of the scalar fields. At zero temperature this theory describes a system of parallel separated extremal D3-branes. Non-zero temperature corresponds to non-extremality in supergravity description. We interpret the supergravity interaction potential between a non-extremal D3-brane and a D3-brane probe as contribution of massive states to the free energy of the N → ∞ SYM theory at strong 't Hooft coupling (λ = 2N g 2 YM ≫ 1). Both low (M ≫ T) and high (T ≫ M) temperature regimes are considered. For low temperature we find that the structure of terms that appear in the free energy at strong and weak coupling is the same. The analysis of the high-temperature regime depends on a careful identification of the scalar field v.e.v. in terms of the distance between branes in the supergravity description and again predicts strong coupling terms similar to those found in the weak-coupling N = 4 SYM theory. We consider also the corrections to the strong coupling results by taking into account the leading α ′3 R 4 string contribution to the supergravity effective action. This gives rise to the λ −3/2 corrections in the coefficient functions of λ which multiply different terms in free energy.

Physics Letters B, Apr 1, 1982

Nuclear Physics B, Dec 1, 1979

A renormalization group block-spin scheme for Z(2) gauge theory is constructed using a hamiltonia... more A renormalization group block-spin scheme for Z(2) gauge theory is constructed using a hamiltonian formulation. The renormalization group equations enable us to calculate the critical coupling and critical exponents both in 2 + 1 and 3 + 1 dimensions. The results compare favorably with those of the Ising model in a transverse field in the 2 + 1 case. In 3 + 1 dimensions the results turn out to satisfy the selfduality constraint. The critical exponents obtained are in agreement with the Migdal conjecture.

Physics Letters B, Aug 1, 1979

We analyze a local Z(2) lattice gauge theory which contains both gauge and matter degrees of free... more We analyze a local Z(2) lattice gauge theory which contains both gauge and matter degrees of freedom. In the twoparameter space of this model we identify matter-screening (MS) and gauge-screening (GS) regions. Massive level crossing occurs on the boundary between the two regions. This may indicate a first-order phase transition. For D = 2 space dimensions the model is self dual. For D = 3 the dual description has a higher gauge symmetry allowing for the existence of magnetic vortices.

Nuclear Physics B, Aug 1, 1996

We analyze the Coulomb phase of theories of N = 2 SQCD with SU (N c) gauge groups which are conje... more We analyze the Coulomb phase of theories of N = 2 SQCD with SU (N c) gauge groups which are conjectured to have exact electric-magnetic duality. We discuss the duality transformation of the particle spectrum, emphasizing the differences between the general case and the SU (2) case. Some difficulties associated with the definition of the duality transformation for a general gauge group are discussed. We compute the classical monopole spectrum of these theories, and when it is possible we use it to check the consistency of the duality. Generally these theories may have phase transitions between strong and weak coupling, which prevent the semi-classical computation from being useful for checking the duality.

Physical review, Jun 15, 1987

We introduce a generalized concept of differential geometry in which the usual first-order deriva... more We introduce a generalized concept of differential geometry in which the usual first-order derivative is replaced by more general operators, for example, the Virasoro operators. These pseudoderivatives are covariantized by introducing the analogs of spin connections and vierbeins. The resulting field-dependent curvatures and torsions are used to build a "geometrical" Becchi-Rouet-Stora-Tyutin (BRST) operator which plays a role analogous to the "exterior derivative" in the construction of generalized BRST-invanant gauge field theories. Possible geometrical approaches to string fields and dynamics are suggested and partially explored.

Nuclear Physics B, Jul 1, 1993

An analysis of the BRST cohomology of the G G topological models is performed for the case of A (... more An analysis of the BRST cohomology of the G G topological models is performed for the case of A (1) 1 . Invoking a special free field parametrization of the various currents, the cohomology on the corresponding Fock space is extracted. We employ the singular vector structure and fusion rules to translate the latter into the cohomology on the space of irreducible representations. Using the physical states we calculate the characters and partition function, and verify the index interpretation. We twist the energy-momentum tensor to establish an intriguing correspondence between the SL(2) SL(2) model with level k = p q -2 and (p, q) models coupled to gravity.

Nuclear Physics B, 1995

We calculate the partition function of the SU (N ) ( and U (N )) generalized Y M 2 theory defined... more We calculate the partition function of the SU (N ) ( and U (N )) generalized Y M 2 theory defined on an arbitrary Riemann surface. The result which is expressed as a sum over irreducible representations generalizes the Rusakov formula for ordinary Y M 2 theory. A diagrammatic expansion of the formula enables us to derive a Gross-Taylor like stringy description of the model. A sum of 2D string maps is shown to reproduce the gauge theory results. Maps with branch points of degree higher than one, as well as "microscopic surfaces" play an important role in the sum. We discuss the underlying string theory.