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Lattice effect algebras densely embeddable into complete ones

Zdena Riečanová (2011)

Kybernetika

An effect algebraic partial binary operation ø p l u s defined on the underlying set E uniquely introduces partial order, but not conversely. We show that if on a MacNeille completion E ^ of E there exists an effect algebraic partial binary operation ^ then ^ need not be an extension of . Moreover, for an Archimedean atomic lattice effect algebra E we give a necessary and sufficient condition for that ^ existing on E ^ is an extension of defined on E . Further we show that such ^ extending exists at most...

Left-covariant differential calculi on S L q ( N )

Konrad Schmüdgen, Axel Schüler (1997)

Banach Center Publications

We study N 2 - 1 dimensional left-covariant differential calculi on the quantum group S L q ( N ) . In this way we obtain four classes of differential calculi which are algebraically much simpler as the bicovariant calculi. The algebra generated by the left-invariant vector fields has only quadratic-linear relations and posesses a Poincaré-Birkhoff-Witt basis. We use the concept of universal (higher order) differential calculus associated with a given left-covariant first order differential calculus. It turns out...

Les équations de Dirac-Fock

Maria J. Esteban, Eric Séré (1997/1998)

Séminaire Équations aux dérivées partielles

Les équations de Dirac-Fock sont l’analogue relativiste des équations de Hartree-Fock. Elles sont utilisées dans les calculs numériques de la chimie quantique, et donnent des résultats sur les électrons dans les couches profondes des atomes lourds. Ces résultats sont en très bon accord avec les données expérimentales. Par une méthode variationnelle, nous montrons l’existence d’une infinité de solutions des équations de Dirac-Fock “sans projecteur", pour des systèmes coulombiens d’électrons dans...

Lieb–Thirring inequalities with improved constants

Jean Dolbeault, Ari Laptev, Michael Loss (2008)

Journal of the European Mathematical Society

Following Eden and Foias we obtain a matrix version of a generalised Sobolev inequality in one dimension. This allows us to improve on the known estimates of best constants in Lieb–Thirring inequalities for the sum of the negative eigenvalues for multidimensional Schrödinger operators.

Liftings of 1-forms to some non product preserving bundles

Doupovec, Miroslav, Kurek, Jan (1998)

Proceedings of the 17th Winter School "Geometry and Physics"

Summary: The article is devoted to the question how to geometrically construct a 1-form on some non product preserving bundles by means of a 1-form on an original manifold M . First, we will deal with liftings of 1-forms to higher-order cotangent bundles. Then, we will be concerned with liftings of 1-forms to the bundles which arise as a composition of the cotangent bundle with the tangent or cotangent bundle.

Limit distributions of many-particle spectra and q-deformed Gaussian variables

Piotr Śniady (2006)

Banach Center Publications

We find the limit distributions for a spectrum of a system of n particles governed by a k-body interaction. The hamiltonian of this system is modelled by a Gaussian random matrix. We show that the limit distribution is a q-deformed Gaussian distribution with the deformation parameter q depending on the fraction k/√n. The family of q-deformed Gaussian distributions include the Gaussian distribution and the semicircular law; therefore our result is a generalization of the results of Wigner [Wig1,...

Limitations on the control of Schrödinger equations

Reinhard Illner, Horst Lange, Holger Teismann (2006)

ESAIM: Control, Optimisation and Calculus of Variations

We give the definitions of exact and approximate controllability for linear and nonlinear Schrödinger equations, review fundamental criteria for controllability and revisit a classical “No-go” result for evolution equations due to Ball, Marsden and Slemrod. In Section 2 we prove corresponding results on non-controllability for the linear Schrödinger equation and distributed additive control, and we show that the Hartree equation of quantum chemistry with bilinear control ( E ( t ) · x ) u is not controllable...

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