33,010 research outputs found
Exploring Vacuum Structure around Identity-Based Solutions
We explore the vacuum structure in bosonic open string field theory expanded
around an identity-based solution parameterized by . Analyzing the
expanded theory using level truncation approximation up to level 20, we find
that the theory has the tachyon vacuum solution for . We also find
that, at , there exists an unstable vacuum solution in the expanded
theory and the solution is expected to be the perturbative open string vacuum.
These results reasonably support the expectation that the identity-based
solution is a trivial pure gauge configuration for , but it can be
regarded as the tachyon vacuum solution at .Comment: 12 pages, 5 figures; new numerical data up to level (20,60) included;
Contribution to the proceedings of "Second International Conference on String
Field Theory and Related Aspects" (Steklov Mathematical Institute, Moscow,
Russia, April 12-19, 2009
Open String Field Theory around Universal Solutions
We study the physical spectrum of cubic open string field theory around
universal solutions, which are constructed using the matter Virasoro operators
and the ghost and anti-ghost fields. We find the cohomology of the new BRS
charge around the solutions, which appear with a ghost number that differs from
that of the original theory. Considering the gauge-unfixed string field theory,
we conclude that open string excitations perturbatively disappear after the
condensation of the string field to the solutions.Comment: 14 pages, LaTeX with ptptex.cls, typos correcte
Susceptibility of the Spin 1/2 Heisenberg Antiferromagnetic Chain
Highly accurate results are presented for the susceptibility, of
the Heisenberg antiferromagnetic chain for all temperatures, using the
Bethe ansatz and field theory methods. After going through a rounded peak,
approaches its asympotic zero-temperature value with infinite slope.Comment: 8 pages and 3 postscript figures appended (uuencoded), Revtex, Report
#:UBCTP-94-00
Hierarchical Mass Matrices in a Minimal SO(10) Grand Unification I
We consider a minimal SO(10) unified model with horizontal Peccei-Quinn
symmetry. The hierarchical structure of quark-lepton mass matrices is naturally
implemented by the remnants of certain irrelevant terms. Georgi-Jarlskog
relations are also realized due to the horizontal symmetry.Comment: phyzzx and tables, 15 pages, KUNS 125
Regularization of identity based solution in string field theory
We demonstrate that an Erler-Schnabl type solution in cubic string field
theory can be naturally interpreted as a gauge invariant regularization of an
identity based solution. We consider a solution which interpolates between an
identity based solution and ordinary Erler-Schnabl one. Two gauge invariant
quantities, the classical action and the closed string tadpole, are evaluated
for finite value of the gauge parameter. It is explicitly checked that both of
them are independent of the gauge parameter.Comment: 9 pages, minor typos corrected and references adde
Nonlinearly Realized Extended Supergravity
We provide nonlinear realization of supergravity with an arbitrary number of
supersymmetries by means of coset construction. The number of gravitino degrees
of freedom counts the number of supersymmetries, which will be possibly probed
in future experiments. We also consider goldstino embedding in the construction
to discuss the relation to nonlinear realization with rigid supersymmetries.Comment: 19 page
Pre-K-Edge Structure on Anomalous X-Ray Scattering in LaMnO3
We study the pre-K-edge structure of the resonant X-ray scattering for
forbidden reflections (anomalous scattering) in LaMnO3, using the band
calculation based on the local density approximation. We find a two-peak
structure with an intensity approximately 1/100 of that of the main peak. This
originates from a mixing of 4p states of Mn to 3d states of neighboring Mn
sites. The effect is enhanced by an interference with the tail of the main
peak. The effect of the quadrupole transition is found to be one order of
magnitude smaller than that of the dipole transition, modifying slightly the
azimuthal-angle dependence.Comment: 4 pages, 5 figures, submitted to J. Phys. Soc. Jp
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