We determine all complex K3 surfaces with Picard rank 20 over Q. Here the NéronSeveri group has rank 20 and is generated by divisors which are defined over Q. Our proof uses modularity, the Artin-Tate conjecture and class group theory. With different techniques, the result has been established by Elkies to show that Mordell-Weil rank 18 over Q is impossible for an elliptic K3 surface. We also a...

An index theory for projective families of elliptic pseudodifferential operators is developed when the twisting, i.e. Dixmier-Douady, class is decomposable in H(X;Z)∪H(X;Z) ⊂ H(X;Z). One of the features of this special case is that the corresponding Azumaya bundle can be realized in terms of smoothing operators. The topological and the analytic index of a projective family of elliptic operators...

August 29, 2013 Version 1.8.12 Date 2013/01/11 Title Analysis of habitat selection by animals Author Clement Calenge, contributions from Mathieu Basille, Stephane Dray and Scott Fortmann-Roe Maintainer Clement Calenge Depends R (>= 2.10.0), ade4, tkrplot, shapefiles Suggests gpclib, sp, spatstat, MASS, CircStats Description A collection of tools for the analysis ...

A combinatorial formula for the Pontrjagin classes of a triangulated manifold is given. The main ingredients are oriented matroid theory and a modified formulation of Chern-Weil theory.

We show that every bad orbifold vector bundle can be realized as the restriction of a good orbifold vector bundle to a suborbifold of the base space. We give an explicit construction of this result in which the Chen-Ruan orbifold cohomology of the two base spaces are isomorphic (as additive groups). This construction is used to indicate an extension of the Chern-Weil construction of characteris...

We show that every bad orbifold vector bundle can be realized as the restriction of a good orbifold vector bundle to a suborbifold of the base space. We give an explicit construction of this result in which the Chen-Ruan orbifold cohomology of the two base spaces are isomorphic (as additive groups). This construction is used to indicate an extension of the Chern-Weil construction of characteris...

March 27, 2015 Version 1.8.17 Date 2015-03-27 Title Analysis of Habitat Selection by Animals Author Clement Calenge, contributions from Mathieu Basille, Stephane Dray and Scott Fortmann-Roe Maintainer Clement Calenge Depends R (>= 2.10.0), ade4, tkrplot, shapefiles, sp, graphics Suggests spatstat, MASS, CircStats Description A collection of tools for the analysis...

we deduce that H(X) = Z[x0, · · · , xr]/(σ1, · · · , σr+1), where σi is the i th elementary symmetric function of r + 1 variables. In particular it follows that H(X) ≃ Z (because Σxi = 0). Remark. Let us consider the case of general G now. According to the BorelBott-Weil theorem there is one-to-one correspondence between irreducible highest weight representations of the Lie algebra g of G and l...

Prevalence of agglutinating antibodies against certain leptospiral serotypes were investigated in man, domestic animals and rodents of Pakistan. In man L. grippotyphosa (14.2%), in cow L. pomona (50.9), in buffalo L. pomona (20.0%), in sheep L. australis (51.4%), in goat L. pyrogenes (30.7%) in R. norvegicus L. grippotyphosa (65.2%) and in Suncus murinus L. grippotyphosa (20.0%) were found as m...

The Mumford class κ1 on Mg,0 was shown to be proportional to the cohomology class [ωWP ] of the Weil-Petersson form by Wolpert in [WO]. Furthermore he showed that the restriction of this class to any component of the compactyfying divisor coincides with the corresponding Weil-Petersson class. Arbarello and Cornalba introduced classes κ1 on Mg,n, proved a similar restriction property for these a...