Finite Lattice Hamiltonian Computations in the P-Representation: the Schwinger Model

The Schwinger model is studied in a finite lattice by means of the P-representation. The vacuum energy, mass gap and chiral condensate are evaluated showing good agreement with the expected values in the continuum limit.Comment: 6 pages, 5 eps figures, espcrc

Test of Information Theory on the Boltzmann Equation

We examine information theory using the steady-state Boltzmann equation. In a nonequilibrium steady-state system under steady heat conduction, the thermodynamic quantities from information theory are calculated and compared with those from the steady-state Boltzmann equation. We have found that information theory is inconsistent with the steady-state Boltzmann equation.Comment: 12 page

Properties of high-z galaxies as seen through lensing clusters

We discuss the first results obtained on the study of a sample of high-z galaxies (2 < z < 7), using the gravitational amplification effect in the core of lensing clusters. Sources are located close to the critical lines in clusters with well constrained mass distributions, and selected through photometric redshifts, computed on a large wavelength domain, and lens inversion techniques.Comment: 5 pages, 3 figures, Conference Proceedings of the "Clustering at High Redshift" Conference, June 29 to July 2, 1999, Marseille (France

Thermal Expansion and Magnetostriction Studies of a Kondo Lattice Compound: Ceagsb2

We have investigated a single crystal of CeAgSb2 using low field ac-susceptibility, thermal expansion and magnetostriction measurements in the temperature range 1.5K to 90K. The ac-susceptibility exhibits a sharp peak at 9.7K for both B//c and B perp c due to the magnetic ordering of the Ce moment. The thermal expansion coefficient alpha, exhibits highly anisotropic behaviour between 3K and 80K : alpha is positive for dL/L perp c, but negative for dL/L // c. Furthermore, alpha (for dL/L) perp c (i.e. in ab-plane) exhibits a sharp peak at TN followed by a broad maximum at 20K, while a sharp negative peak at TN followed by a minimum at 20K has been observed for (dL/L //) the c direction. The observed maximum and minimum in alpha(T) at 20K have been attributed to the crystalline field effect on the J=5/2 state of the Ce3+ ion. The magnetostriction also exhibits anisotropic behaviour with a large magnetostriction along the c-axis. The ab-plane magnetostriction exhibits a peak at B=3.3T at 3K, which is consistent with the observed peak in the magnetoresistance measurements.Comment: 4 Pages (B5), 3 figures, submitted to SCES200