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Finite temperature field theory with boundaries: The photon field
442
ABSTRACTS
OF PAPERS TO APPEAR IN FUTURE ISSUES
the First Order of the Hyperspherical Harmonic Expansion Method. M. FABRE DE LA RIPELLE, Institut de Physique Nucleaire, 91406 Orsay Cedex, France, AND H. FIEDELDEY* AND G. WIECHERS,’ *Department of Physics, and +Department of Computer Science and Information Systems, University of South Africa, Pretoria, South Africa.
Beyond
In this paper we demonstrate the inadequacy of the first order of the Hyperspherical Harmonic Expansion Method, the L, approximation, for the calculation of the binding energies, charge form factors and charge densities of doubly magic nuclei like I50 and 40Ca. We then extend the Hyperspherical Expansion Method to many-fermion systems, consisting of an arbitrary number of fermions, and develop an exact formalism capable of generating the complete optimal subset of the hyperspherical harmonic basis functions. This optimal subset of those hyperspherical harmonic basis functions directly connected to the dominant first term in the expansion, the hyperspherical harmonic of minimal order L,, through the total interaction between the particles. The required many-body coefficients are given using either the Gogny or Talmi-Moshinsky coefftcients for the two-body operators. Using the two-body coefficients the weight function generating the orthogonal polynomials associated with the optimal subset. Temperature Field Theory with Boundaries: The Photon Field. GERARD KENNEDY. Institute for Theoretical Physics, University of California, Santa Barbara, California 93 106, and Center for Relativity, Department of Physics. University of Texas at Austin, Austin, Texas 787 12.
Finite
We calculate the deviations from Planckian form of the photon field finite temperature stress tensor in a manifold with boundary, due to scattering from the boundary. Familiar non-integrable divergences are found in the photon stress tensor as the boundary is approached and these are shown to be an inescapable consequence of initial calculational assumptions. Modifications of these assumptions are discussed which serve to remove the divergences and to illustrate the importance of the role played by surface gravitational actions,
A Study
of the Leptodermous
Expansion
of the
Binding
Energy
in Finite
Nuclei.
B.
GRAMMATICOS.
Laboratoire de Physique Nucleaire Theorique, CRN, Strasbourg, France. The validity of the leptodermous expansion of the binding energy of nuclear systems is studied. First, a soluble model, in the one dimensional case, which is suitable for the study of such effects is briefly recalled and subsequently generalized to allow for variable nuclear compressibility. A mass formula with exponential terms which are necessary for the description of light systems is introduced. We show that the determination of its parameters does not require any new fits. They are completely determined once one allows for breakdown of the leptodermous expansion for very small systems.
ABSTRACTS
OF PAPERS TO APPEAR IN FUTURE ISSUES
the First Order of the Hyperspherical Harmonic Expansion Method. M. FABRE DE LA RIPELLE, Institut de Physique Nucleaire, 91406 Orsay Cedex, France, AND H. FIEDELDEY* AND G. WIECHERS,’ *Department of Physics, and +Department of Computer Science and Information Systems, University of South Africa, Pretoria, South Africa.
Beyond
In this paper we demonstrate the inadequacy of the first order of the Hyperspherical Harmonic Expansion Method, the L, approximation, for the calculation of the binding energies, charge form factors and charge densities of doubly magic nuclei like I50 and 40Ca. We then extend the Hyperspherical Expansion Method to many-fermion systems, consisting of an arbitrary number of fermions, and develop an exact formalism capable of generating the complete optimal subset of the hyperspherical harmonic basis functions. This optimal subset of those hyperspherical harmonic basis functions directly connected to the dominant first term in the expansion, the hyperspherical harmonic of minimal order L,, through the total interaction between the particles. The required many-body coefficients are given using either the Gogny or Talmi-Moshinsky coefftcients for the two-body operators. Using the two-body coefficients the weight function generating the orthogonal polynomials associated with the optimal subset. Temperature Field Theory with Boundaries: The Photon Field. GERARD KENNEDY. Institute for Theoretical Physics, University of California, Santa Barbara, California 93 106, and Center for Relativity, Department of Physics. University of Texas at Austin, Austin, Texas 787 12.
Finite
We calculate the deviations from Planckian form of the photon field finite temperature stress tensor in a manifold with boundary, due to scattering from the boundary. Familiar non-integrable divergences are found in the photon stress tensor as the boundary is approached and these are shown to be an inescapable consequence of initial calculational assumptions. Modifications of these assumptions are discussed which serve to remove the divergences and to illustrate the importance of the role played by surface gravitational actions,
A Study
of the Leptodermous
Expansion
of the
Binding
Energy
in Finite
Nuclei.
B.
GRAMMATICOS.
Laboratoire de Physique Nucleaire Theorique, CRN, Strasbourg, France. The validity of the leptodermous expansion of the binding energy of nuclear systems is studied. First, a soluble model, in the one dimensional case, which is suitable for the study of such effects is briefly recalled and subsequently generalized to allow for variable nuclear compressibility. A mass formula with exponential terms which are necessary for the description of light systems is introduced. We show that the determination of its parameters does not require any new fits. They are completely determined once one allows for breakdown of the leptodermous expansion for very small systems.