Searcharxiv⌕ Search

arXiv subjects

Anastasia Volovich

Publications and source records attributed to Anastasia Volovich.

At least 109 records · Page 6Linked to original sources
arXiv2003

Note on Plane Wave Quantum Mechanics

We study the quantum mechanics of BMN operators with two scalar impurities and arbitrarily many traces, at one loop and all genus. We prove an operator identity which partially elucidates the structure of this quantum mechanics, provides some support for a conjectured formula for the free all genus two-point functions, and demonstrates that a single O(g_2^2) contact term arises in the Hamiltonian as a result of transforming from the natural gauge theory basis to the string basis. We propose to identify the S-matrix of this quantum mechanics with the S-matrix of string theory in the plane-wave background.

hep-th↗
arXiv2002

Explicit Formulas for Neumann Coefficients in the Plane-Wave Geometry

We obtain explicit formulas for the Neumann coefficients and associated quantities that appear in the three-string vertex for type IIB string theory in a plane-wave background, for any value of the mass parameter mu. The derivation involves constructing the inverse of a certain infinite-dimensional matrix, in terms of which the Neumann coefficients previously had been written only implicitly. We derive asymptotic expansions for large mu and find unexpectedly simple results, which are valid to all orders in 1/mu. Using BMN duality, these give predictions for certain gauge theory quantities to all orders in the modified 't Hooft coupling lambda'. A specific example is presented.

hep-th↗
arXiv2002

Tracing the String: BMN correspondence at Finite J^2/N

Employing the string bit formalism of hep-th/0209215, we identify the basis transformation that relates BMN operators in N=4 gauge theory to string states in the dual string field theory at finite g_2=J^2/N. In this basis, the supercharge truncates at linear order in g_2, and the mixing amplitude between 1 and 2-string states precisely matches with the (corrected) answer of hep-th/0206073 for the 3-string amplitude in light-cone string field theory. Supersymmetry then predicts the order g_2^2 contact term in the string bit Hamiltonian. The resulting leading order mass renormalization of string states agrees with the recently computed shift in conformal dimension of BMN operators in the gauge theory.

hep-th↗
arXiv2002

On light-cone SFT contact terms in a plane wave

Testing the BMN correspondence at non-zero string coupling g_s requires a one-loop string field theory calculation. At order g_s^2, matrix elements of the light-cone string field theory Hamiltonian between single-string states receive two contributions: the iterated cubic interaction, and a contact term {Q, Q} whose presence is dictated by supersymmetry. In this paper we calculate the leading large mu p^+ alpha' contribution from both terms for the set of intermediate states with two string excitations. We find precise agreement with the basis-independent order g_2^2 results from gauge theory.

hep-th↗
arXiv2002

Superstring Interactions in a pp-wave Background

We construct light-cone gauge superstring field theory in a pp-wave background with Ramond-Ramond flux. The leading term in the interaction Hamiltonian is determined up to an overall function of $p^+$ by requiring closure of the pp-wave superalgebra. The bosonic and fermionic Neumann matrices for this cubic vertex are derived, as is the interaction point operator. We comment on the development of a $1/μp^+$ expansion for these results.

hep-th↗
arXiv2002

Superstring Interactions in a pp-wave Background II

In type IIB light-cone superstring field theory, the cubic interaction has two pieces: a delta-functional overlap and an operator inserted at the interaction point. In this paper we extend our earlier work hep-th/0204146 by computing the matrix elements of this operator in the oscillator basis of pp-wave string theory for all mu p^+ alpha'. By evaluating these matrix elements for large mu p^+ alpha', we check a recent conjecture relating matrix elements of the light-cone string field theory Hamiltonian (with prefactor) to certain three-point functions of BMN operators in the gauge theory. We also make several explicit predictions for gauge theory.

hep-th↗
arXiv2002

New Effects in Gauge Theory from pp-wave Superstrings

It has recently been observed that IIB string theory in the pp-wave background can be used to calculate certain quantities, such as the dimensions of BMN operators, as exact functions of the effective coupling lambda' = lambda/J^2. These functions interpolate smoothly between the weak and strong effective coupling regimes of N=4 SYM theory at large R charge J. In this paper we use the pp-wave superstring field theory of hep-th/0204146 to study more complicated observables. The expansion of the three-string interaction vertex suggests more complicated interpolating functions which in general give rise to fractional powers of lambda' in physical observables at weak effective coupling.

hep-th↗
arXiv2002

Noncommutative solitons on Kahler manifolds

We construct a new class of scalar noncommutative multi-solitons on an arbitrary Kahler manifold by using Berezin's geometric approach to quantization and its generalization to deformation quantization. We analyze the stability condition which arises from the leading 1/hbar correction to the soliton energy and for homogeneous Kahler manifolds obtain that the stable solitons are given in terms of generalized coherent states. We apply this general formalism to a number of examples, which include the sphere, hyperbolic plane, torus and general symmetric bounded domains. As a general feature we notice that on homogeneous manifolds of positive curvature, solitons tend to attract each other, while if the curvature is negative they will repel each other. Applications of these results are discussed.

hep-th↗
arXiv2002

Vacuum States and the S-Matrix in dS/CFT

We propose a definition of dS/CFT correlation functions by equating them to S-matrix elements for scattering particles from I^- to I^+. In planar coordinates, which cover half of de Sitter space, we consider instead the S-vector obtained by specifying a fixed state on the horizon. We construct the one-parameter family of de Sitter invariant vacuum states for a massive scalar field in these coordinates, and show that the vacuum obtained by analytic continuation from the sphere has no particles on the past horizon. We use this formalism to provide evidence that the one-parameter family of vacua corresponds to marginal deformations of the CFT by computing a three-point function.

hep-th↗
arXiv2001

Les Houches Lectures on De Sitter Space

These lectures present an elementary discussion of some background material relevant to the problem of de Sitter quantum gravity. The first two lectures discuss the classical geometry of de Sitter space and properties of quantum field theory on de Sitter space, especially the temperature and entropy of de Sitter space. The final lecture contains a pedagogical discussion of the appearance of the conformal group as an asymptotic symmetry group, which is central to the dS/CFT correspondence. A (previously lacking) derivation of asymptotically de Sitter boundary conditions is also given.

hep-th↗
arXiv2001

Two-Black-Hole Bound States

The quantum mechanics of $N$ slowly-moving BPS black holes in five dimensions is considered. A divergent continuum of states describing arbitrarily closely bound black holes with arbitrarily small excitation energies is found. A superconformal structure appears at low energies and can be used to define an index counting the weighted number of supersymmetric bound states. It is shown that the index is determined from the dimensions of certain cohomology classes on the symmetric product of $N$ copies of $R^4$. An explicit computation for the case of N=2 with no angular momentum yields a finite nonzero result.

hep-th↗
arXiv2001

Discreteness in deSitter Space and Quantization of Kahler Manifolds

Recently, it has been proposed that the dimension of the Hilbert space of quantum gravity in deSitter space is finite and moreover it is expressed in terms of the coupling constants by using the entropy formula. A weaker conjecture would be that the coupling constant in deSitter space should take only discrete values not necessarily given by the entropy formula. We discuss quantization of the horizon in deSitter space by using Berezin's functorial quantization of Kahler manifolds and argue that the weak conjecture is valid for Euclidean deSitter space. Moreover it can be valid for a class of bounded complex symmetric spaces.

hep-th↗
arXiv1999

Holography for Coset Spaces

M/string theory on noncompact, negatively curved, cosets which generalize $AdS_{D+1}=SO(D,2)/SO(D,1)$ is considered. Holographic descriptions in terms of a conformal field theory on the boundary of the spacetime are proposed. Examples include $SU(2,1)/U(2)$, which is a Euclidean signature (4,0) space with no supersymmetry, and $SO(2,2)/SO(2)$ and $SO(3,2)/SO(3)$, which are Lorentzian signature (4,1) and (6,1) spaces with eight supersymmetries. Qualitatively new features arise due to the degenerate nature of the conformal boundary metric.

hep-th↗
arXiv1998

Rarita-Schwinger Field in the AdS/CFT Correspondence

A free Rarita-Schwinger field in the Anti-de Sitter space is considered. We show that the usual action can be supplemented by a boundary term that can be interpreted as the generating functional of the correlation functions in a conformal field theory on the boundary of the Anti-de Sitter space.

hep-th↗
arXiv1998

Domain Walls in MQCD and Monge-Ampere Equation

We study Witten's proposal that a domain wall exists in M-theory fivebrane version of QCD (MQCD) and that it can be represented as a supersymmetric three-cycle in G_2 holonomy manifold. It is shown that equations defining the U(1) invariant domain wall for SU(2) group can be reduced to the Monge-Ampere equation. A proof of an algebraic formula of Kaplunovsky, Sonnenschein and Yankielowicz is presented. The formal solution of equations for domain wall is constructed.

hep-th↗
arXiv1997

Domain Wall in MQCD and Supersymmetric Cycles in Exceptional Holonomy Manifolds

It was conjectured by Witten that a BPS-saturated domain wall exists in the M-theory fivebrane version of QCD (MQCD) and can be represented as a supersymmetric three-cycle in the sense of Becker et al with an appropriate asymptotic behavior. We derive the differential equation which defines an associative cycle in $G_2$ holonomy seven-manifold corresponding to the supersymmetric three-cycle and show that it contains a sum of the Poisson brackets. We study solutions of the differential equation with prescribed asymptotic behavior.

hep-th↗