ar X iv : c on d - m at / 9 90 83 26 v 1 2 4 A ug 1 99 9 Gaudin Hypothesis for the XY Z Spin Chain

ar X iv : c on d - m at / 9 90 83 26 v 3 2 N ov 1 99 9 Gaudin Hypothesis for the XY Z Spin Chain

The XY Z spin chain is considered in the framework of the generalized algebraic Bethe ansatz developed by Takhtajan and Faddeev. The sum of norms of the Bethe vectors is computed and expressed in the form of a Jacobian. This result corresponds to the Gaudin hypothesis for the XY Z spin chain.

ar X iv : c on d - m at / 9 60 31 90 v 1 2 9 M ar 1 99 6 The Four - Dimensional XY Spin Glass

v 2 4 S ep 1 99 9 Gaudin Hypothesis for the XY Z Spin Chain

The XY Z spin chain is considered in the framework of the generalized algebraic Bethe ansatz developed by Takhtajan and Faddeev. The sum of norms of the Bethe vectors is computed and expressed in the form of a Jacobian. This result corresponds to the Gaudin hypothesis for the XY Z spin chain.

ar X iv : c on d - m at / 9 90 83 59 v 1 2 5 A ug 1 99 9 Dilatancy and friction in sheared granular media

We introduce a simple model to describe the frictional properties of granular media under shear. We model the friction force in terms of the horizontal velocity ẋ and the vertical position z of the slider, interpreting z as a constitutive variable characterizing the contact. Dilatancy is shown to play an essential role in the dynamics, inducing a stick-slip instability at low velocity. We compu...

ar X iv : c on d - m at / 9 20 80 13 v 1 1 9 A ug 1 99 2 Effect of Matrix Elements on the Pairing Kernel in Exchange Mediated Superconductors

A method is derived for calculating the pairing kernel in exchange mediated su-perconductors including matrix element effects. Various models for the interaction vertex are considered, including spin exchange, orbital exchange, and quadrupo-lar exchange. As an example, this formalism is applied to U P t 3 using relativistic wavefunctions from a local density band calculation.