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Fermi Golden Rule, Feshbach Method and embedded point spectrum

Jan Dereziński (1998/1999)

Séminaire Équations aux dérivées partielles

A method to study the embedded point spectrum of self-adjoint operators is described. The method combines the Mourre theory and the Limiting Absorption Principle with the Feshbach Projection Method. A more complete description of this method is contained in a joint paper with V. Jak s ˇ ić, where it is applied to a study of embedded point spectrum of Pauli-Fierz Hamiltonians.

Ferromagnetic integrals, correlations and maximum principles

Johannes Sjöstrand (1994)

Annales de l'institut Fourier

For correlations of the form (0.2) we consider a critical case and prove power decay upper bounds in terms of the fundamental solution of a certain elliptic operator. This is achieved by improving the use of a maximum principle. We also formulate a general maximum principle and give two applications.

First-order semidefinite programming for the two-electron treatment of many-electron atoms and molecules

David A. Mazziotti (2007)

ESAIM: Mathematical Modelling and Numerical Analysis


The ground-state energy and properties of any many-electron atom or molecule may be rigorously computed by variationally computing the two-electron reduced density matrix rather than the many-electron wavefunction. While early attempts fifty years ago to compute the ground-state 2-RDM directly were stymied because the 2-RDM must be constrained to represent an N-electron wavefunction, recent advances in theory and optimization have made direct computation of the 2-RDM possible. The constraints in...

From multi-instantons to exact results

Jean Zinn-Justin (2003)

Annales de l’institut Fourier

In these notes, conjectures about the exact semi-classical expansion of eigenvalues of hamiltonians corresponding to potentials with degenerate minima, are recalled. They were initially motivated by semi-classical calculations of quantum partition functions using a path integral representation and have later been proven to a large extent, using the theory of resurgent functions. They take the form of generalized Bohr--Sommerfeld quantization formulae. We explain here their...

Fundamental solutions for Dirac-type operators

Swanhild Bernstein (1996)

Banach Center Publications

We consider the Dirac-type operators D + a, a is a paravector in the Clifford algebra. For this operator we state a Cauchy-Green formula in the spaces C 1 ( G ) and W p 1 ( G ) . Further, we consider the Cauchy problem for this operator.

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