Search results for "String cosmology"

showing 8 items of 8 documents

String fields as limit of functions and surface terms in string field theory

1989

We consider the String Field Theory proposed by Witten in the discretized approach, where the string is considered as the limit N → ∞ of a collection of N points. In this picture the string functional is the limit of a succession of functions of an increasing number of variables; an object with some resemblances to distributions. Attention is drawn to the fact that the convergence is not of the uniform kind, and that therefore exchanges of limits, sums and integral signs can cause problems, and be ill defined. In this context we discuss some surface terms found by Woodard, which arise in integrations by parts, and argue that they depend crucially on the choice of the successions of functio…

PhysicsNuclear and High Energy PhysicsCompactification (physics)DiscretizationFísicaAstronomy and AstrophysicsString field theoryTopological string theoryRelationship between string theory and quantum field theoryAtomic and Molecular Physics and OpticsNon-critical string theoryTheoretical physicsQuantum mechanicsString cosmologyBoundary value problem
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THE SPACE OF STRING CONFIGURATIONS IN STRING FIELD THEORY

1990

In this paper we consider the set of maps from the interval [0, π] which constitute the argument of the functionals of a String Field Theory. We show that in order to correctly reproduce results of the dual model one has to include all square integrable functions in the functional integral, or Ω0 in terms of Sobolev spaces.

PhysicsNuclear and High Energy PhysicsCompactification (physics)FísicaAstronomy and AstrophysicsString field theoryType I string theoryRelationship between string theory and quantum field theoryAtomic and Molecular Physics and OpticsSobolev spaceNon-critical string theoryTheoretical physicsClassical mechanicsSquare-integrable functionString cosmologyInternational Journal of Modern Physics A
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Computation of Amplitudes in the Discretized Approach to String Field Theory

1988

An approach to Witten string field theory based on the discretization of the world sheet is adopted. We use it to calculate tree amplitudes with the formulation of the theory based on string functionals. The results are evaluated numerically and turn out to be very accurate, giving, for a string approximated by 600 points, values within 0.02% of the prediction of the dual model. The method opens a way to calculate amplitudes in string field theory using nonflat backgrounds as well as compactified dimensions.

PhysicsCompactification (physics)Mathematical analysisS-dualityFísicaGeneral Physics and AstronomyString field theoryTopological string theoryHigh Energy Physics::TheoryNon-critical string theoryQuantum electrodynamicsString cosmologyDilatonQuantum field theoryPhysical Review Letters
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Holomorphic Aspects of String Theory

1989

A string is a piecewise smooth map of the interval to a manifold M. A closed string is a map of the circle S1 into M. In string theory the strings replace the points of the manifold M as fundamental objects. The enormous amount of work done on quantized string models in physics has been motivated by the hope that the quantum string theory would produce a finite quantized theory of gravity, free of the divergences of the ordinary quantized Einstein theory of gravitation. So far the proof is missing but work is continuing. It has been proposed that some kind of string theory would be the unified theory of all fundamental interactions in physics. However, the fundamental principles of string t…

High Energy Physics::TheoryNon-critical string theoryCompactification (physics)String cosmologyString field theoryType I string theoryTopological string theoryString theoryString (physics)Mathematical physicsMathematics
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NON-PERTURBATIVE VACUUM WAVE-FUNCTIONAL AND CLOSED STRING EQUATIONS OF MOTION

1989

The anomalous conformal dependence of the vacuum wave-functional is studied in the non-perturbative regime of the closed bosonic string theory. It is shown that the vanishing of the vacuum expectation value of the stress-energy tensor trace leads to the implementation of a suitable variational condition on the wave-functional, provided that the dilaton condensate be taken as a conformal compensator for the graviton condensate of the embedding space.

PhysicsNuclear and High Energy PhysicsQED vacuumBosonic string theoryGravitonGeneral Physics and AstronomyAstronomy and AstrophysicsString field theoryGeneral Relativity and Quantum CosmologyNon-critical string theoryClassical mechanicsString cosmologyDilatonVacuum expectation valueModern Physics Letters A
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Bose-Fermi equivalence and interacting string field theory

1995

Abstract We show that the bosonic and the fermionic realization of the ghost vertex in the Half-String (HS) Operator approach to Witten's String Field Theory (WSFT) are equivalent. In the process we discover that higher vertices (i.e., N > 3) can be eliminated in WSFT using only the overlap conditions defining the interaction vertex and ghost number counting.

PhysicsHeterotic string theoryBosonizationNuclear and High Energy PhysicsCompactification (physics)High Energy Physics::LatticeFísicaString field theoryRelationship between string theory and quantum field theoryVertex (geometry)Non-critical string theoryHigh Energy Physics::TheoryQuantum mechanicsString cosmologyParticle Physics - TheoryMathematical physics
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The three-vertex in the closed half-string field theory and the general gluing and resmoothing theorem

1997

In this letter we prove that the half-string three-vertex in closed string field theory satisfies the general gluing and resmoothing theorem. We also demonstrate how one calculates amplitudes in the half-string approach to closed string field theory, by working out explicitly a few simple three-amplitudes.

Pure mathematicsCompactification (physics)General Physics and AstronomyStatistical and Nonlinear PhysicsString field theoryType I string theoryRelationship between string theory and quantum field theoryCombinatoricsHigh Energy Physics::TheoryNon-critical string theoryString phenomenologyQuantum gravityString cosmologyMathematical PhysicsMathematicsJournal of Physics A: Mathematical and General
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The transverse structure of the QCD string

2010

The characterization of the transverse structure of the QCD string is discussed. We formulate a conjecture as to how the stress-energy tensor of the underlying gauge theory couples to the string degrees of freedom. A consequence of the conjecture is that the energy density and the longitudinal-stress operators measure the distribution of the transverse position of the string, to leading order in the string fluctuations, whereas the transverse-stress operator does not. We interpret recent numerical measurements of the transverse size of the confining string and show that the difference of the energy and longitudinal-stress operators is the appropriate probe to use when comparing with the nex…

PhysicsHigh Energy Physics - TheoryNuclear and High Energy PhysicsCompactification (physics)High Energy Physics - Lattice (hep-lat)FOS: Physical sciencesString field theoryTopological string theoryString theoryNon-critical string theoryDomain wall (string theory)High Energy Physics::TheoryHigh Energy Physics - LatticeHigh Energy Physics - Theory (hep-th)Quantum mechanicsString cosmologyString dualityMathematical physics
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