Báo cáo toán học: "Short generating functions for some semigroup algebras" doc

... 91–147. MR 2000k:52014 the electronic journal of combinatorics 10 (2003), #R36 6 Short generating functions for some semigroup algebras Graham Denham ∗ Department of Mathematics University of Western ... Sengupta, AGr¨obner basis for certain affine monomial curves, Comm. Algebra 31 (2003), no. 3, 1113–1129. MR 1 971 052 [12] L. A. Sz´ekely and N. C. Wormald, Generating functions...

Ngày tải lên: 07/08/2014, 08:20

Ngày tải lên: 05/08/2014, 10:20

... ,v n }ofnvertices,wesaythatalabeledtournamentT  onVisconsistentwithH ifT  isisomorphictoTandcontainsalledgesinH.Considerthefollowingprocedureforproducing anisomorphismcertificate.Initially,defineH 0 =∅andletT 0 bethesetofalltournamentsonV whichareconsistentwithH 0 (thatis;thesetofalltournamentswhichareisomorphictoT.)Note thatT 0 containsn!/|Aut(T)|tournaments,whereAut(T)istheautomorphismgroup...

Ngày tải lên: 07/08/2014, 06:20

... decomposition formula (Theorem 4) for the Bartholdi zeta function of semiregular bipartite graph. As a corollary, we obtain a decomposition formula for the Bartholdi zeta function of some regular ... V i are mutually nonadjacent for i = 1, 2. A bipartite graph G = (V 1 , V 2 ) is called (q 1 +1, q 2 +1)-semiregular if deg G v = q i +1 for each v ∈ V i (i = 1, 2). For a (q 1 + 1, q...

Ngày tải lên: 07/08/2014, 13:21

... (see for example [8]) that if for some graph valued random variables G 1 and G 2 d T V (G 1 , G 2 ) = o(1), the electronic journal of combinatorics 18 (2011), #P36 6 Sharp threshold functions for ... the threshold functions for other properties of G (n, m, p). However we present here graph properties for which the threshold functions obtained by our method are tight at least...

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Ngày tải lên: 05/08/2014, 15:20

Ngày tải lên: 05/08/2014, 15:20

... The previous best lower bound for R(5, 5, 5) was 169 given by Song [S], who more generally shows that R(5, 5, ,5    rtimes )≥4(6.48) r−1 +1 holds for all r.ForR(6, 6, 6) there was no established ... avoid monochro- matic triangles. Harvesting Some Lower Bounds for Ramsey Numbers It is amazing that the result of this section has not been observed for the 25 years since [C] was pu...

Ngày tải lên: 07/08/2014, 06:20

... l j ≥ l s for all j>s. Suppose that l j <l s for some j>s. By the induction hypothesis, (k  ,l  ) is a admissible pair, and therefore (s, j − 1) is not an irregular position for it. ... admissible, and k (1) i ≤ k (1) s 1 for all i. It implies that l (1) j ≥ l (1) s 1 for all j>s 1 and l (1) j ≤ l (1) s 1 for all j, p r ≤ j ≤ s 1 − 1. The same is true for l (2) ....

Ngày tải lên: 07/08/2014, 07:21

... L n . Therefore by induction π = π 0 π n−2 π n−1 with π j ∈ R L j for all 0 ≤ j ≤ n − 1. For example, let π =[3, 5, −4, 2, −1], then π 3 = a 3 a 2 a 1 ; ππ −1 3 =[−4, 3, 2, −1, 5], there- fore π 2 = ... 3.1 and 3.3]. For a proof of the general case, see for example [2, Ch. 3.3]. the electronic journal of combinatorics 11 (2004), #R83 3 From this formulation one sees immediately that...

Ngày tải lên: 07/08/2014, 08:22