19,198 research outputs found
Spatial pseudoanalytic functions arising from the factorization of linear second order elliptic operators
Biquaternionic Vekua-type equations arising from the factorization of linear
second order elliptic operators are studied. Some concepts from classical
pseudoanalytic function theory are generalized onto the considered spatial
case. The derivative and antiderivative of a spatial pseudoanalytic function
are introduced and their applications to the second order elliptic equations
are considered.Comment: 17 page
Zakharov-Shabat system and hyperbolic pseudoanalytic function theory
In [1] a hyperbolic analogue of pseudoanalytic function theory was developed.
In the present contribution we show that one of the central objects of the
inverse problem method the Zakharov-Shabat system is closely related to a
hyperbolic Vekua equation for which among other results a generating sequence
and hence a complete system of formal powers can be constructed explicitly.Comment: 9 page
An analogue of the Sommerfeld radiation condition for the Dirac operator
A simple radiation condition at infinity for time-harmonic massive Dirac
spinors is proposed. This condition allows an analogue of the Cauchy integral
formula in unbounded domains for null-solutions of the Dirac equation to be
proved. The result is obtained with the aid of methods of quaternionic
analysis.Comment: 15 pages, 1 figur
On the reduction of the multidimensional Schroedinger equation to a first order equation and its relation to the pseudoanalytic function theory
Given a particular solution of a one-dimensional stationary Schroedinger
equation (SE) this equation of second order can be reduced to a first order
linear differential equation. This is done with the aid of an auxiliary Riccati
equation. We show that a similar fact is true in a multidimensional situation
also. We consider the case of two or three independent variables. One
particular solution of (SE) allows us to reduce this second order equation to a
linear first order quaternionic differential equation. As in one-dimensional
case this is done with the aid of an auxiliary Riccati equation. The resulting
first order quaternionic equation is equivalent to the static Maxwell system.
In the case of two independent variables it is the Vekua equation from theory
of generalized analytic functions. We show that even in this case it is
necessary to consider not complex valued functions only, solutions of the Vekua
equation but complete quaternionic functions. Then the first order quaternionic
equation represents two separate Vekua equations, one of which gives us
solutions of (SE) and the other can be considered as an auxiliary equation of a
simpler structure. For the auxiliary equation we always have the corresponding
Bers generating pair, the base of the Bers theory of pseudoanalytic functions,
and what is very important, the Bers derivatives of solutions of the auxiliary
equation give us solutions of the main Vekua equation and as a consequence of
(SE). We obtain an analogue of the Cauchy integral theorem for solutions of
(SE). For an ample class of potentials (which includes for instance all radial
potentials), this new approach gives us a simple procedure allowing to obtain
an infinite sequence of solutions of (SE) from one known particular solution
Wave polynomials, transmutations and Cauchy's problem for the Klein-Gordon equation
We prove a completeness result for a class of polynomial solutions of the
wave equation called wave polynomials and construct generalized wave
polynomials, solutions of the Klein-Gordon equation with a variable
coefficient. Using the transmutation (transformation) operators and their
recently discovered mapping properties we prove the completeness of the
generalized wave polynomials and use them for an explicit construction of the
solution of the Cauchy problem for the Klein-Gordon equation. Based on this
result we develop a numerical method for solving the Cauchy problem and test
its performance.Comment: 31 pages, 8 figures (16 graphs
B Spectroscopy at Tevatron
Recent results on heavy flavor spectroscopy from the CDF and D0 experiments
are reported in this contribution. Using up to 1 fb-1 of accumulated luminosity
per experiment, properties of X(3872), excited B** states, and the B_c meson
are measured. Also included are measurements of production rates for ground
state b hadrons in ppbar collisions.Comment: This paper reflects the presentation on B spectroscopy at the Flavor
Physics and CP Violation'06 conference in Vancouver, Apr 9-12, 2006. To be
published in conferences proceeding
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