6,253 research outputs found
Composite boson dominance in many-fermion systems
I recently proposed a method of bosonization based on the use of coherent
states of fermion composites, whose validity was restricted to smooth structure
functions. In the present paper I remove this limitation and derive results
which hold for arbitrary interactions and structure functions. The method
respects all symmetries and in particular fermion number conservation. It
reproduces exactly the results of the pairing model of atomic nuclei and of the
BCS model of superconductivity in the number conserving form of the
quasi-chemical equilibrium theory.Comment: 5 pages, no figur
Composite bosons and quasiparticles in a number conserving approach
I recently proposed a method of bosonization valid for systems of an even
number of fermions whose partition function is dominated at low energy by
bosonic composites. This method respects all symmetries, in particular fermion
number conservation. I extend it to treat odd systems and excitations involving
unpaired fermions.Comment: To be published in the proceedings of the conference "Changing facets
of nuclear structure" Vico Equense, May 20-24 200
Path integrals and degrees of freedom in many-body systems and relativistic field theories
The identification of physical degrees of freedom is sometimes obscured in
the path integral formalism, and this makes it difficult to impose some
constraints or to do some approximations. I review a number of cases where the
difficulty is overcame by deriving the path integral from the operator form of
the partition function after such identification has been made.Comment: 15 pages, volume in honor of prof.Yu.A.Simono
Boson Dominance in nuclei
We present a new method of bosonization of fermion systems applicable when
the partition function is dominated by composite bosons. Restricting the
partition function to such states we get an euclidean bosonic action from which
we derive the Hamiltonian. Such a procedure respects all the fermion
symmetries, in particular fermion number conservation, and provides a boson
mapping of all fermion operators.Comment: 12 page
User's guide to programming fault injection and data acquisition in the SIFT environment
Described are the features, command language, and functional design of the SIFT (Software Implemented Fault Tolerance) fault injection and data acquisition interface software. The document is also intended to assist and guide the SIFT user in defining, developing, and executing SIFT fault injection experiments and the subsequent collection and reduction of that fault injection data. It is also intended to be used in conjunction with the SIFT User's Guide (NASA Technical Memorandum 86289) for reference to SIFT system commands, procedures and functions, and overall guidance in SIFT system programming
Bosonization and even Grassmann variables
A new approach to bosonization in relativistic field theories and many-body
systems, based on the use of fermionic composites as integration variables in
the Berezin integral defining the partition function of the system, is tested.
The method is applied to the study of a simplified version of the BCS model.Comment: 20 pages, LaTe
- …