02 05 5 v 1 8 F eb 2 00 3 Burgers ’ equation in non - commutative space - time

/ 06 02 05 8 v 1 6 F eb 2 00 6 The Parametrized Relativistic Particle and the Snyder space - time

Using the parametrized relativistic particle we obtain the noncommutative Snyder space-time. In addition, we study the consistency conditions between the boundary conditions and the canonical gauges that give origin to noncommutative theories. Using these results we construct a first order action, in the reduced phase-space, for the Snyder particle with momenta fixed on the boundary. Pacs: 11.1...

/ 02 02 04 0 v 1 6 F eb 2 00 2 Anomalies in Noncommutative Dipole Field Theories

We study chiral symmetries of fermionic non commutative dipole theories. By using Fujikawa's approach we obtain explicit expressions of the anomalies for Dirac and chiral fermions in 2 and 4 dimensions.

ar X iv : a st ro - p h / 05 02 17 5 v 1 8 F eb 2 00 5 The velocity field of baryonic gas in the universe

The dynamic evolution of the baryonic intergalactic medium (IGM) caused by the underlying dark matter gravity is governed by the Navier-Stokes equations in which many cooling and heating processes are involved. However, it has long been recognized that the growth mode dynamics of cosmic matter clustering can be sketched by a random force driven Burgers’ equation if cooling and heating are ignor...

ar X iv : m at h / 05 02 09 4 v 1 [ m at h . D G ] 4 F eb 2 00 5 THE SECOND YAMABE INVARIANT

Let (M, g) be a compact Riemannian manifold of dimension n ≥ 3. We define the second Yamabe invariant as the infimum of the second eigenvalue of the Yamabe operator over the metrics conformal to g and of volume 1. We study when it is attained. As an application, we find nodal solutions of the Yamabe equation.

/ 05 02 08 5 v 1 4 F eb 2 00 5 An energetic blast wave from the December 27 giant flare of the soft γ - ray repeater 1806 - 20