8,655 research outputs found
Properties of scalar perturbations generated by conformal scalar field
Primordial scalar perturbations may be generated when complex conformal
scalar field rolls down its negative quartic potential. We begin with the
discussion of peculiar infrared properties of this scenario. We then consider
the statistical anisotropy inherent in the model. Finally, we discuss the
non-Gaussianity of scalar perturbations. Because of symmetries, the bispectrum
vanishes identically. We present a general expression for the trispectrum and
give its explicit form in the folded limit.Comment: Prepared for "Gravity and Cosmology (GC2010)" workshop, Kyoto, Japan,
May,24-July,16, 2010; 15 pages, 1 figur
Octonic Electrodynamics
In this paper we present eight-component values "octons", generating
associative noncommutative algebra. It is shown that the electromagnetic field
in a vacuum can be described by a generalized octonic equation, which leads
both to the wave equations for potentials and fields and to the system of
Maxwell's equations. The octonic algebra allows one to perform compact combined
calculations simultaneously with scalars, vectors, pseudoscalars and
pseudovectors. Examples of such calculations are demonstrated by deriving the
relations for energy, momentum and Lorentz invariants of the electromagnetic
field. The generalized octonic equation for electromagnetic field in a matter
is formulated.Comment: 12 pages, 1 figur
Superpolynomials for toric knots from evolution induced by cut-and-join operators
The colored HOMFLY polynomials, which describe Wilson loop averages in
Chern-Simons theory, possess an especially simple representation for torus
knots, which begins from quantum R-matrix and ends up with a trivially-looking
split W representation familiar from character calculus applications to matrix
models and Hurwitz theory. Substitution of MacDonald polynomials for characters
in these formulas provides a very simple description of "superpolynomials",
much simpler than the recently studied alternative which deforms relation to
the WZNW theory and explicitly involves the Littlewood-Richardson coefficients.
A lot of explicit expressions are presented for different representations
(Young diagrams), many of them new. In particular, we provide the
superpolynomial P_[1]^[m,km\pm 1] for arbitrary m and k. The procedure is not
restricted to the fundamental (all antisymmetric) representations and the torus
knots, still in these cases some subtleties persist.Comment: 23 pages + Tables (51 pages
New method of verifying cryptographic protocols based on the process model
A cryptographic protocol (CP) is a distributed algorithm designed to provide
a secure communication in an insecure environment. CPs are used, for example,
in electronic payments, electronic voting procedures, database access systems,
etc. Errors in the CPs can lead to great financial and social damage, therefore
it is necessary to use mathematical methods to justify the correctness and
safety of the CPs. In this paper, a new mathematical model of a CP is
introduced, which allows one to describe both the CPs and their properties. It
is shown how, on the base of this model, it is possible to solve the problems
of verification of CPs
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