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Let M (let + m)

Distribution by Scientific Domains
Mathematics and Statistics75%

Selected Abstracts

Deligne's duality for de Rham realizations of 1-motives

MATHEMATISCHE NACHRICHTEN, Issue 12 2009
Alessandra Bertapelle
Abstract Let M be a 1-motive over a base scheme S and M , its Cartier dual. We show the existence of a canonical duality between the de Rham realizations of M and M ,; this generalizes a result in [5]. Furthermore, we study universal extensions of 1-motives and their relation with ,-extensions (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Expanding the additive reduct of a model of Peano arithmetic

MLQ- MATHEMATICAL LOGIC QUARTERLY, Issue 4 2003
Masahiko Murakami
Abstract Let M be a model of first order Peano arithmetic (PA) and I an initial segment of M that is closed under multiplication. LetM0 be the {0, 1,+}-reduct ofM. We show that there is another model N of PA that is also an expansion of M0 such that a · Ma = a · Na if and only if a , I for all a , M. [source]

Nonstationary weak limit of a stationary harmonic map sequence

COMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 2 2003
Weiyue Ding
Let M and N be two compact Riemannian manifolds. Let uk be a sequence of stationary harmonic maps from M to N with bounded energies. We may assume that it converges weakly to a weakly harmonic map u in H1,2 (M, N) as k , ,. In this paper, we construct an example to show that the limit map u may not be stationary. © 2002 Wiley Periodicals, Inc. [source]

Coloring uniform hypergraphs with few edges

RANDOM STRUCTURES AND ALGORITHMS, Issue 3 2009
A.V. Kostochka
Abstract A hypergraph is b-simple if no two distinct edges share more than b vertices. Let m(r, t, g) denote the minimum number of edges in an r -uniform non- t -colorable hypergraph of girth at least g. Erd,s and Lovász proved that A result of Szabó improves the lower bound by a factor of r2,, for sufficiently large r. We improve the lower bound by another factor of r and extend the result to b -simple hypergraphs. We also get a new lower bound for hypergraphs with a given girth. Our results imply that for fixed b, t, and , > 0 and sufficiently large r, every r -uniform b -simple hypergraph with maximum edge-degree at most trr1,, is t -colorable. Some results hold for list coloring, as well. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009 [source]