21 research outputs found
Towards Integrability of Topological Strings I: Three-forms on Calabi-Yau manifolds
The precise relation between Kodaira-Spencer path integral and a particular
wave function in seven dimensional quadratic field theory is established. The
special properties of three-forms in 6d, as well as Hitchin's action
functional, play an important role. The latter defines a quantum field theory
similar to Polyakov's formulation of 2d gravity; the curious analogy with
world-sheet action of bosonic string is also pointed out.Comment: 31 page
Backgrounds in Boundary String Field Theory
We study the role of closed string backgrounds in boundary string field
theory. Background independence requires the introduction of dual boundary
fields, which are reminiscent of the doubled field formalism. We find a
correspondence between closed string backgrounds and collective excitations of
open strings described by vertex operators involving dual fields.
Renormalization group flow, solutions and stability are discussed in an
example.Comment: Contribution to proceedings of SFT09 in 'Theoretical and Mathematical
Physics', Russian Academy of Science
Non-orientable Boundary Superstring Field theory with Tachyon field
We use the BSFT method to study the unoriented open string field theory (type
I). The partition function on the Mobius strip is calculated. We find that, at
the one-loop level, the divergence coming from planar graph and unoriented
graph cancel each other as expected.Comment: 17 pages, 2 figures, references adde
N D0-branes and antibranes in the background independent string field theory
In this paper we extend our previous work hep-th/0102063 to the case
D0-brane+antibrane system.Comment: 20 page
Noncommutativity and Tachyon Condensation
We study the fuzzy or noncommutative Dp-branes in terms of infinitely many
unstable D0-branes, from which we can construct any Dp-branes. We show that the
tachyon condensation of the unstable D0-branes induces the noncommutativity. In
the infinite tachyon condensation limit, most of the unstable D0-branes
disappear and remaining D0-branes are actually the BPS D0-branes with the
correct noncommutative coordinates. For the fuzzy S^2 case, we explicitly show
only the D0-branes corresponding to the lowest Landau level survive in the
limit. We also show that a boundary state for a Dp-brane satisfying the
Dirichlet boundary condition on a curved submanifold embedded in the flat space
is not localized on the submanifold. This implies that the Dp-brane on it is
ambiguous at the string scale and solves the problem for a spherical D2-brane
with a unit flux on the world volume which should be equivalent to one
D0-brane. We also discuss the diffeomorphism in the D0-brane picture.Comment: 30 pages, references added, minor corrections and clarifications,
version to appear in JHE
Higgs Bundles, Gauge Theories and Quantum Groups
The appearance of the Bethe Ansatz equation for the Nonlinear Schr\"{o}dinger
equation in the equivariant integration over the moduli space of Higgs bundles
is revisited. We argue that the wave functions of the corresponding
two-dimensional topological U(N) gauge theory reproduce quantum wave functions
of the Nonlinear Schr\"{o}dinger equation in the -particle sector. This
implies the full equivalence between the above gauge theory and the
-particle sub-sector of the quantum theory of Nonlinear Schr\"{o}dinger
equation. This also implies the explicit correspondence between the gauge
theory and the representation theory of degenerate double affine Hecke algebra.
We propose similar construction based on the gauged WZW model leading to
the representation theory of the double affine Hecke algebra. The relation with
the Nahm transform and the geometric Langlands correspondence is briefly
discussed.Comment: 48 pages, typos corrected, one reference adde
Sigma model approach to string theory effective actions with tachyons
Motivated by recent discussions of actions for tachyon and vector fields
related to tachyon condensation in open string theory we review and clarify
some aspects of their derivation within sigma model approach. In particular, we
demonstrate that the renormalized partition function of boundary sigma
model gives the effective action for massless vectors which is consistent with
string S-matrix and beta function, resolving an old problem with this
suggestion in bosonic string case at the level of the leading
derivative corrections to Born-Infeld action. We give manifestly gauge
invariant definition of in non-abelian NSR open string theory and
check that its derivative reproduces the tachyon beta function in a particular
scheme. We also discuss derivation of similar actions for tachyon and massless
modes in closed bosonic and NSR (type 0) string theories.Comment: 26 pages, harvmac. To appear in the special issue of J. Math. Phys.
on Strings, Branes and M-theory. v4: minor editorial changes, version to
appear in JM
Boundary String Field Theory of the DDbar System
We develop the boundary string field theory approach to tachyon condensation
on the DDbar system. Particular attention is paid to the gauge fields, which
combine with the tachyons in a natural way. We derive the RR-couplings of the
system and express the result in terms of Quillen's superconnection. The result
is related to an index theorem, and is thus shown to be exact.Comment: 38 pages, harvmac. v2: added reference
Closed String Tachyon Condensation: An Overview
These notes are an expanded version of a review lecture on closed string
tachyon condensation at the RTN workshop in Copenhagen in September 2003. We
begin with a lightning review of open string tachyon condensation, and then
proceed to review recent results on localized closed string tachyon
condensation, focusing on two simple systems, C/Z_n orbifolds and twisted
circle compactifications.Comment: harvmac, 59 pages; references adde
Tachyon Condensation and Background Independent Superstring Field Theory
We study quantum corrections at the one loop level in open superstring
tachyon condensation using the boundary string field theory (BSFT) method. We
find that the tachyon field action has the same form as at the disc level, but
with a renormalized effective coupling
( is the renormalized dimensionless closed string coupling,
is the tachyonic field expectation value) and with an effective
string tension. This result is in agreement with that based on general analysis
of loop effects.Comment: 22 pages, LaTe