20,587 research outputs found
Constant of step-by-step ionization of atoms
Constant of step by step ionization of atomic gase
On the determination of the earthquake slip distribution via linear programming techniques
The description that one can have of the seismic source is the mani-
festation of an imagined model, obviously outlined from Physic Theories
and supported by mathematical methods. In that context, the modelling
of earthquake rupture consists in finding values of the parameters of the
selected physics-mathematical model, through which it becomes possible
to reproduce numerically the records of earthquake effects on the Earths
surface. We present and test a Linear Programming (LP) inversion in dual
form, for reconstructing the kinematics of the rupture of large earthquakes
through space-time seismic slip distribution on finite faults planes
An Algorithm to Construct Groebner Bases for Solving Integration by Parts Relations
This paper is a detailed description of an algorithm based on a generalized
Buchberger algorithm for constructing Groebner-type bases associated with
polynomials of shift operators. The algorithm is used for calculating Feynman
integrals and has proven itself efficient in several complicated cases.Comment: LaTeX, 9 page
Free field representation for the O(3) nonlinear sigma model and bootstrap fusion
The possibility of the application of the free field representation developed
by Lukyanov for massive integrable models is investigated in the context of the
O(3) sigma model. We use the bootstrap fusion procedure to construct a free
field representation for the O(3) Zamolodchikov- Faddeev algebra and to write
down a representation for the solutions of the form-factor equations which is
similar to the ones obtained previously for the sine-Gordon and SU(2) Thirring
models. We discuss also the possibility of developing further this
representation for the O(3) model and comment on the extension to other
integrable field theories.Comment: 14 pages, latex, revtex v3.0 macro package, no figures Accepted for
publication in Phys. Rev.
Form-factors of the sausage model obtained with bootstrap fusion from sine-Gordon theory
We continue the investigation of massive integrable models by means of the
bootstrap fusion procedure, started in our previous work on O(3) nonlinear
sigma model. Using the analogy with SU(2) Thirring model and the O(3) nonlinear
sigma model we prove a similar relation between sine-Gordon theory and a
one-parameter deformation of the O(3) sigma model, the sausage model. This
allows us to write down a free field representation for the
Zamolodchikov-Faddeev algebra of the sausage model and to construct an integral
representation for the generating functions of form-factors in this theory. We
also clear up the origin of the singularities in the bootstrap construction and
the reason for the problem with the kinematical poles.Comment: 16 pages, revtex; references added, some typos corrected. Accepted
for publication in Physical Review
Neutrino Mass and New Physics
We review the present state of and future outlook for our understanding of
neutrino masses and mixings. We discuss what we think are the most important
perspectives on the plausible and natural scenarios for neutrinos and what may
have the most promise to throw light on the flavor problem of quarks and
leptons. We focus on the seesaw mechanism which fits into the big picture of
particle physics such as supersymmetry and grand unification providing a
unified approach to flavor problem of quarks and leptons. We argue that in
combination with family symmetries, this may be at the heart of a unified
understanding of flavor puzzle. We also discuss other new physics ideas such as
neutrinos in models with extra dimensions and possible theoretical implications
of sterile neutrinos. We outline some tests for the various schemes.Comment: 90 pages and 9 figures; With permission from the Annual Review of
Nuclear and Particle Science. Final version of this material is scheduled to
appear in the Annual Review of Nuclear and Particle Science Vol. 56, to be
published in November 2006 by Annual Reviews (http://www.annualreviews.org);
some references and parts of text update
On orthogonal expansions of the space of vector functions which are square-summable over a given domain and the vector analysis operators
The Hilbert space L2(omega) of vector functions is studied. A breakdown of L2(omega) into orthogonal subspaces is discussed and the properties of the operators for projection onto these subspaces are investigated from the standpoint of preserving the differential properties of the vectors being projected. Finally, the properties of the operators are examined
On the Resolution of Singularities of Multiple Mellin-Barnes Integrals
One of the two existing strategies of resolving singularities of multifold
Mellin-Barnes integrals in the dimensional regularization parameter, or a
parameter of the analytic regularization, is formulated in a modified form. The
corresponding algorithm is implemented as a Mathematica code MBresolve.mComment: LaTeX, 10 page
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