3,524 research outputs found
Additional Comments on the Application of Statistical Analysis to Differential Pass-Fail Rates in Employment Testing
Abelian Gauge Theory in de Sitter Space
Quantization of spinor and vector free fields in 4-dimensional de Sitter
space-time, in the ambient space notation, has been studied in the previous
works. Various two-points functions for the above fields are presented in this
paper. The interaction between the spinor field and the vector field is then
studied by the abelian gauge theory. The U(1) gauge invariant spinor field
equation is obtained in a coordinate independent way notation and their
corresponding conserved currents are computed. The solution of the field
equation is obtained by use of the perturbation method in terms of the Green's
function. The null curvature limit is discussed in the final stage.Comment: 10 pages, typos corrected, reference adde
On the plane-wave cubic vertex
The exact bosonic Neumann matrices of the cubic vertex in plane-wave
light-cone string field theory are derived using the contour integration
techniques developed in our earlier paper. This simplifies the original
derivation of the vertex. In particular, the Neumann matrices are written in
terms of \mu-deformed Gamma-functions, thus casting them into a form that
elegantly generalizes the well-known flat-space solution. The asymptotics of
the \mu-deformed Gamma-functions allow one to determine the large-\mu behaviour
of the Neumann matrices including exponential corrections. We provide an
explicit expression for the first exponential correction and make a conjecture
for the subsequent exponential correction terms.Comment: 26 pages, 1 figure; harvmac (b); v4: minor corrections in appendix
On the exact open-closed vertex in plane-wave light-cone string field theory
The open-closed vertex in the maximally supersymmetric type IIB plane-wave
light-cone string field theory is considered and an explicit solution for the
bosonic part of the vertex is derived, valid for all values of the mass
parameter, \mu. This vertex is of relevance to IIB plane-wave orientifolds, as
well as IIB plane-wave strings in the presence of D-branes and their gauge
theory duals. Methods of complex analysis are used to develop a systematic
procedure for obtaining the solution. This procedure is first applied to the
vertex in flat space and then extended to the plane-wave case. The plane-wave
solution for the vertex requires introducing certain ``\mu-deformed Gamma
functions'', which are generalizations of the ordinary Gamma function. The
behaviour of the Neumann matrices is graphically illustrated and their
large-\mu asymptotics are analysed.Comment: 35 pages, 7 figures; v4: minor changes in appendi
Quantum Entropy Function from AdS(2)/CFT(1) Correspondence
We review and extend recent attempts to find a precise relation between
extremal black hole entropy and degeneracy of microstates using AdS_2/CFT_1
correspondence. Our analysis leads to a specific relation between degeneracy of
black hole microstates and an appropriately defined partition function of
string theory on the near horizon geometry, -- named the quantum entropy
function. In the classical limit this reduces to the usual relation between
statistical entropy and Wald entropy.Comment: LaTeX file, 27 pages, A modified and extended version of the talk
given at Strings 200
PP-Wave Light-Cone Free String Field Theory at Finite Temperature
In this paper, a real-time formulation of light-cone pp-wave string field
theory at finite temperature is presented. This is achieved by developing the
thermo field dynamics (TFD) formalism in a second quantized string scenario.
The equilibrirum thermodynamic quantities for a pp-wave ideal string gas are
derived directly from expectation values on the second quantized string thermal
vacuum. Also, we derive the real-time thermal pp-wave closed string propagator.
In the flat space limit it is shown that this propagator can be written in
terms of Theta functions, exactly as the zero temperature one. At the end, we
show how supestrings interactions can be introduced, making this approach
suitable to study the BMN dictionary at finite temperature.Comment: 27 pages, revtex
Light-cone Superstring Field Theory, pp-wave background and integrability properties
We show that the three strings vertex coefficients in light--cone open string
field theory satisfy the Hirota equations for the dispersionless Toda lattice
hierarchy. We show that Hirota equations allow us to calculate the correlators
of an associated quantum system where the Neumann coefficients represent the
two--point functions. We consider next the three strings vertex coefficients of
the light--cone string field theory on a maximally supersymmetric pp--wave
background. Using the previous results we are able to show that these Neumann
coefficients satisfy the Hirota equations for the full Toda lattice hierarchy
at least up to second order in the 'string mass' .Comment: 23 pages, 3 figures, footnote and references adde
Squeezed States in the de Sitter Vacuum
We discuss the treatment of squeezed states as excitations in the Euclidean
vacuum of de Sitter space. A comparison with the treatment of these states as
candidate no-particle states, or alpha-vacua, shows important differences
already in the free theory. At the interacting level alpha-vacua are
inconsistent, but squeezed state excitations seem perfectly acceptable. Indeed,
matrix elements can be renormalized in the excited states using precisely the
standard local counterterms of the Euclidean vacuum. Implications for
inflationary scenarios in cosmology are discussed.Comment: 15 pages, no figures. One new citation in version 3; no other change
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 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 expansion for these results.Comment: 35 pages, 3 figures. v3:typos fixed, a couple of helpful remarks
added (including one un-commented out from the v1 source file
Collinear and Soft Limits of Multi-Loop Integrands in N=4 Yang-Mills
It has been argued in arXiv:1112.6432 that the planar four-point integrand in
N=4 super Yang-Mills theory is uniquely determined by dual conformal invariance
together with the absence of a double pole in the integrand of the logarithm in
the limit as a loop integration variable becomes collinear with an external
momentum. In this paper we reformulate this condition in a simple way in terms
of the amplitude itself, rather than its logarithm, and verify that it holds
for two- and three-loop MHV integrands for n>4. We investigate the extent to
which this collinear constraint and a constraint on the soft behavior of
integrands can be used to determine integrands. We find an interesting
complementarity whereby the soft constraint becomes stronger while the
collinear constraint becomes weaker at larger n. For certain reasonable choices
of basis at two and three loops the two constraints in unison appear strong
enough to determine MHV integrands uniquely for all n.Comment: 27 pages, 14 figures; v2: very minor change
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