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1.
A. Ganchev 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):173-175
The invertible objects in a tensor category form a subcategory the Grothendieck ring of which is the group ring of an abelian
group. This abelian fusion ring acts on the objects of the initial category and one can in principle determine all 6j-symbols that contain the lable of an invertible object.
Received 1st October 2001 / Received in final form 12 April 2002 Published online 2 October 2002
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ID="a"e-mail: ganchev@inrne.bas.bg 相似文献
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B. G. Ganchev V. M. Kozlov V. V. Orlov 《Journal of Applied Mechanics and Technical Physics》1972,13(2):256-259
The characteristic features of stroboscopic visualization and the possibilities of using this method for studying the flow of thin films are considered. The velocity field and the field of turbulent pulsations are studied experimentally for the film flow of liquids with Reynolds numbers of R = 40–1770.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 140–143, March–April, 1972. 相似文献
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Alexander H. Ganchev William Greenberg C. V. M. van der Mee 《Integral Equations and Operator Theory》1988,11(4):518-535
Krein space methods are used to derive the unique solvability of a class of abstract kinetic equations on a half-space with accretive collision operators. At the same time a new proof is provided for the case of a positive self-adjoint collision operator. A Fokker-Planck type example is worked out as a new application.This work was performed while the author resided at the Dept. of Physics and Astronomy of the Free University of Amsterdam, The Netherlands. 相似文献
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On any timelike surface with zero mean curvature in the four-dimensional Minkowski space we introduce special geometric (canonical) parameters and prove that the Gauss curvature and the normal curvature of the surface satisfy a system of two natural partial differential equations. Conversely, any two solutions to this system determine a unique (up to a motion) timelike surface with zero mean curvature so that the given parameters are canonical. We find all timelike surfaces with zero mean curvature in the class of rotational surfaces of Moore type. These examples give rise to a one-parameter family of solutions to the system of natural partial differential equations describing timelike surfaces with zero mean curvature. 相似文献
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The Kähler manifolds of quasi-constant holomorphic sectional curvatures are introduced as Kähler manifolds with complex distribution of codimension two, whose holomorphic sectional curvature only depends on the corresponding point and the geometric angle, associated with the section. A curvature identity characterizing such manifolds is found. The biconformal group of transformations whose elements transform Kähler metrics into Kähler ones is introduced and biconformal tensor invariants are obtained. This makes it possible to classify the manifolds under consideration locally. The class of locally biconformal flat Kähler metrics is shown to be exactly the class of Kähler metrics whose potential function is only a function of the distance from the origin in ? n . Finally we show that any rotational even dimensional hypersurface carries locally a natural Kähler structure which is of quasi-constant holomorphic sectional curvatures. 相似文献
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We construct a commutative ring with identity which extends the ring of characters of finite dimensional representations of
sl(3). It is generated by characters with values in the group ring of the extended affine Weyl group of at . The “quantised” version at rational level k+3=3/p realises the fusion rules of a WZW conformal field theory based on admissible representations of .
Received: 22 September 1998 / Accepted: 24 November 1998 相似文献
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The jump operator on the ω-enumeration degrees was introduced in [I.N. Soskov, The ω-enumeration degrees, J. Logic Computat. 17 (2007) 1193–1214]. In the present paper we prove a jump inversion theorem which allows us to show that the enumeration degrees are first order definable in the structure of the ω-enumeration degrees augmented by the jump operator. Further on we show that the groups of the automorphisms of and of the enumeration degrees are isomorphic.In the second part of the paper we study the jumps of the ω-enumeration degrees below . We define the ideal of the almost zero degrees and obtain a natural characterization of the class H of the ω-enumeration degrees below which are high n for some n and of the class L of the ω-enumeration degrees below which are low n for some n. 相似文献
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Jürgen Fuchs Alexander Ganchev Peter Vecsernyés 《Communications in Mathematical Physics》1992,146(3):553-583
The superselection structure of the Wess-Zumino-Witten theory based on the affine Lie algebra
at level one is investigated for arbitraryN. By making use of the free fermion representation of the affine algebra, the endomorphisms which represent the superselection sectors on the observable algebra can be constructed as endomorphisms of the underlying Majorana algebra. These endomorphisms do not close on the chiral algebra of the theory, but we are able to obtain a larger algebra on which the endomorphisms close. The composition of equivalence classes of the endomorphisms reproduces the WZW fusion rules. 相似文献
10.
We consider different iterative methods for computing Hermitian solutions of the coupled Riccati equations of the optimal control problem for jump linear systems. We have constructed a sequence of perturbed Lyapunov algebraic equations whose solutions define matrix sequences with special properties proved under proper initial conditions. Several numerical examples are included to illustrate the effectiveness of the considered iterations. 相似文献