Báo cáo toán học: "Algebraic properties of edge ideals via combinatorial topology" doc

... journal of combinatorics 16(2) (2009), #R2 5 Algebraic properties of edge ideals via combinatorial topology Anton Dochtermann TU Berlin, MA 6-2 Straße des 17. Juni 136 10623 Berlin Germany dochterm@math.tu-berlin.de Alexander ... called the edge ideal of G. We will often speak of algebraic properties of a graph G and by this we mean the corresponding property of the...

Ngày tải lên: 08/08/2014, 01:20

... Parvatham, R: Properties of a class of functions with bounded boundary rotation. Ann. Polon. Math. 31, 311–323 (1975) [3]. Noor, KI: On radii of convexity and starlikeness of some classes of analytic ... family of integral operator using famous convolution technique. We also apply this newly defined operator for investigating some interesting mapping properties of certai...

Ngày tải lên: 20/06/2014, 21:20

Ngày tải lên: 05/08/2014, 15:21

Ngày tải lên: 05/08/2014, 15:21

... of critical P (r, b) graphs are disjoint unions of b − 1 copies of of complete k-partite graphs in which every part has r − 1 vertices. Other critical graphs can be obtained by adding extra edges ... version of Graffiti made number of conjectures about operations R and B (derived from the chromatic number) and we included a sample of them in the first draft of this paper. Since the...

Ngày tải lên: 07/08/2014, 06:20

... subset of vertices C ⊆ V , and an integer r ≥ 1; for any vertex v ∈ V , let B r (v) denote the ball of radius r centered at v, i.e., the set of all vertices linked to v by a path of at most r edges. If ... s i+2 trivially r-cover the same vertices because r ≥ 3.  Other constructions can be thought of. We give, without proof, one example which gives smaller graphs than the ones in th...

Ngày tải lên: 07/08/2014, 15:22

... a sequence ˜ S of length m which consists of all nonzero eigen- values of X n such that the number of appearences of an eigenvalue is its multiplicity. the electronic journal of combinatorics ... journal of combinatorics 14 (2007), #R45 7 2. The multiplicity of zero as an eigenvalue of X n is n − m. 3. If α(λ) is the multiplicity of the eigenvalue λ of X n , then λα(λ) i...

Ngày tải lên: 07/08/2014, 15:22

... proof of Theorem 28 of [4] can also be adapted to hereditary properties of tour- naments, to produce many properties with different exponential speeds, but we spare the reader the details. Of ... Hereditary properties of combinatorial struc- tures: posets and oriented graphs, to appear in Journal of Graph Theory. [4] J. Balogh, B. Bollob´as and R. Morris, Hereditary proper...

Ngày tải lên: 07/08/2014, 15:23

... even. Problem 3.3 Find a combinatorial proof of Theorem 2.1. Note. The calculations were performed after the talk. There were no violations to the Zeilberger rules of order. Acknowledgement The authors ... valuation of sequences counting Alternating Sign Matrices. Journal of In teger Sequences, 12:1–21, 2009. [5] D. Zeilberger. Proof of the Alternating Sign Matrix conjecture. Elec...

Ngày tải lên: 08/08/2014, 14:23

... 4 Properties of Attachments to Try In order to understand how our technique han- dles the attachments that follow this pattern, it is helpful to consider the properties of this class of ... grammars. Our approach to syntax uses a cascade of rule sequence processors, each of which can be thought of as approximating some aspect of the underlying grammar by finite-state...

Ngày tải lên: 23/03/2014, 19:20