15 research outputs found
On Stable Sector in Supermembrane Matrix Model
We study the spectrum of SU(2) x SO(2) matrix supersymmetric quantum
mechanics. We use angular coordinates that allow us to find an explicit
solution of the Gauss law constraints and single out the quantum number n (the
Lorentz angular momentum). Energy levels are four-fold degenerate with respect
to n and are labeled by n_q, the largest n in a quartet. The Schr\"odinger
equation is reduced to two different systems of two-dimensional partial
differential equations. The choice of a system is governed by n_q. We present
the asymptotic solutions for the systems deriving thereby the asymptotic
formula for the spectrum. Odd n_q are forbidden, for even n_q the spectrum has
a continuous part as well as a discrete one, meanwhile for half-integer n_q the
spectrum is purely discrete. Taking half-integer n_q one can cure the model
from instability caused by the presence of continuous spectrum.Comment: 29 pages, 5 figure
Tachyon condensation in cubic superstring field theory
It has been conjectured that at the stationary point of the tachyon potential
for the non-BPS D-brane or brane-anti-D-brane pair, the negative energy density
cancels the brane tension. We study this conjecture using a cubic superstring
field theory with insertion of a double-step inverse picture changing operator.
We compute the tachyon potential at levels (1/2,1) and (2,6). In the first case
we obtain that the value of the potential at the minimum is 97.5% of the non
BPS D-brane tension. Using a special gauge in the second case we get 105.8% of
the tension.Comment: 19 pages, LaTeX, 3 figures. Eqs. (3.2), (3.3) and (4.6) are
corrected, and new gauge fixing condition is use
Descent Relations in Cubic Superstring Field Theory
The descent relations between string field theory (SFT) vertices are
characteristic relations of the operator formulation of SFT and they provide
self-consistency of this theory. The descent relations and
in the NS fermionic string field theory in the kappa and discrete bases are
established. Different regularizations and schemes of calculations are
considered and relations between them are discussed.Comment: Replaced to JHEP styl
Gauge Invariance and Tachyon Condensation in Cubic Superstring Field Theory
The gauge invariance of cubic open superstring field theory is considered in
a framework of level truncation, and applications to the tachyon condensation
problem are discussed. As it is known, in the bosonic case the Feynman-Siegel
gauge is not universal within the level truncation method. We explore another
gauge that is more suitable for calculation of the tachyon potential for
fermionic string at level (2,6). We show that this new gauge has no
restrictions on the region of its validity at least at this level.Comment: 21 pages, 2 figures, LaTeX 2e; references added, typos correcte
MASS-SPECTRA OF CHEMICAL IONIZATION OF NATURAL MONOXY AND MONOACYLOXYDIHYDROPYRANO AND DIHYDROFUROCOUMARINS
On Schnabl solutions of string field equations
We clarify the relationship between Schnabl's solution and pure gauge configurations. Both Schnabl's and pure gauge solutions are obtained by means of an iterative procedure. We show that the pure gauge string field configuration that is used in the construction of a perturbation series for Schnabl's solution diverges on a large subspace of string configurations, but it can be rendered convergent by adding a compensating term. The additional term ensures the fulfillment of the equations of motion in a weak sense. This compensating term coincides with the term necessary for obtaining an action consistent with Sen's first conjecture. © Pleiades Publishing, Ltd 2009
On Schnabl solutions of string field equations
We clarify the relationship between Schnabl's solution and pure gauge configurations. Both Schnabl's and pure gauge solutions are obtained by means of an iterative procedure. We show that the pure gauge string field configuration that is used in the construction of a perturbation series for Schnabl's solution diverges on a large subspace of string configurations, but it can be rendered convergent by adding a compensating term. The additional term ensures the fulfillment of the equations of motion in a weak sense. This compensating term coincides with the term necessary for obtaining an action consistent with Sen's first conjecture. © Pleiades Publishing, Ltd 2009