ar X iv : 0 90 6 . 52 13 v 1 [ m at h . A G ] 2 9 Ju n 20 09 MODEL CATEGORY STRUCTURES ARISING FROM DRINFELD VECTOR BUNDLES

ar X iv : 0 90 6 . 45 41 v 1 [ m at h . PR ] 2 4 Ju n 20 09 Covariance function of vector self - similar process ∗

The paper obtains the general form of the cross-covariance function of vector fractional Brownian motion with correlated components having different self-similarity indices.

ar X iv : m at h / 04 09 02 9 v 1 [ m at h . A G ] 2 S ep 2 00 4 ACM BUNDLES ON GENERAL HYPERSURFACES IN P 5 OF LOW DEGREE

In this paper we show that on a general hypersurface of degree r = 3, 4, 5, 6 in P 5 a rank 2 vector bundle E splits if and only if h 1 E(n) = h 2 E(n) = 0 for all n ∈ Z. Similar results for r = 1, 2 were obtained in [15], [16] and [1].

ar X iv : m at h / 04 09 59 9 v 3 [ m at h . Q A ] 1 A pr 2 00 5 YETTER - DRINFELD MODULES OVER WEAK BIALGEBRAS

We discuss properties of Yetter-Drinfeld modules over weak bialgebras over commutative rings. The categories of left-left, left-right, right-left and right-right Yetter-Drinfeld modules over a weak Hopf algebra are isomorphic as braided monoidal categories. Yetter-Drinfeld modules can be viewed as weak Doi-Hopf modules, and, a fortiori, as weak entwined modules. If H is finitely generated and p...

ar X iv : 0 90 6 . 48 35 v 1 [ m at h . O C ] 2 6 Ju n 20 09 The Complex Gradient Operator and the CR - Calculus

ar X iv : 0 81 1 . 40 90 v 3 [ m at h . Q A ] 2 3 Ju n 20 09 MODULE CATEGORIES OVER POINTED HOPF ALGEBRAS

We develop some techniques for studying exact module categories over some families of pointed finite-dimensional Hopf algebras. As an application we classify exact module categories over the tensor category of representations of the small quantum groups uq(sl2).