Báo cáo toán học: "Matroid inequalities from electrical network theory" docx

... property,orisaHPP matroid. the electronic journal of combinatorics 11(2) (2005), #A1 3 Matroid inequalities from electrical network theory David G. Wagner ∗ Department of Combinatorics and Optimization University ... 1981, Stanley applied the Aleksandrov–Fenchel Inequalities to prove a loga- rithmic concavity theorem for regular matroids. Using ideas from electrical network th...

Ngày tải lên: 07/08/2014, 08:22

... < 1/2) (50) and find from (41) G(x)= 2x 1 −2x − 1 2 + ∞  m=0 (−1) m 2  2m m  x 2m (1 −2x) = 1 2 1 −2x √ 1+4x 2 − 1 2 1 − 6x 1 − 2x . (51) On the other hand we have from (49) G(x)= x 1 − x + ... that the bond is directed from the first to the second index. If d =(i, j) we use the notation ˆ d =(j, i). Let g (i) be the set of directed bonds (i, j) which emanate from the vertex i,and...

Ngày tải lên: 07/08/2014, 06:23

... D 8 which by Lemma 8, apart from the regular orbits it has two orbits of size 4. So in this case N 12 =0. If8|q +3,then = −1andH has a subgroup D 8 which apart from the regular orbits it has ... There are some known results on 3-designs from PGL(2,q) in the literature, see for example [1, 4, 6]. In this paper, we first determine the sizes of orbits from the actions of subgroups of PG...

Ngày tải lên: 07/08/2014, 13:21

Ngày tải lên: 05/08/2014, 15:20

Ngày tải lên: 05/08/2014, 15:20

Ngày tải lên: 05/08/2014, 15:20

... the amount of flow that has to go from A to A. This amount is  v∈A α(v) −  v∈A β(v), The flow leaving A is constrained by the capacity of the cut, i.e., number of edges oriented from A to A in Z, this ... on the choice of three vertices a 1 ,a 2 ,a 3 in clockwise order from the outer face of G.The suspension dual G σ ∗ is obtained from the dual G ∗ by some surgery: The dual-vertex cor...

Ngày tải lên: 07/08/2014, 08:20

... ∈ M k (p)andq is obtained from p by deleting i − 2 entries from 1, ,i− 1 and not deleting i}, B = {q | q ∈ M k (p)andq is obtained from p by deleting i − 2 entries from 1, ,i− 1andi}, C = {q ... should be so that it can be reconstructed from its multiset of (n −k)-minors M k (p), or from the underlying set M  k (p), which in most cases is different from M k (p). In Section 2 of...

Ngày tải lên: 07/08/2014, 13:21

... subtracting 1 from any number that is between i and j and subtracting 2 from any number that is greater than j. Hence, we obtain p ⇓ i ⇓ (j − 1) = p ⇓ j ⇓ i (2.1) for any 1 ≤ i < j ≤ n. From the ... deleting n from p or from q to form t, and thus either (iii) or (iv) is satisfied. Finally, if both p and q contain the 2-cycle (1n), then again the remaining cycles are unchanged by r...

Ngày tải lên: 07/08/2014, 21:21

... whole proof. the electronic journal of combinatorics 17 (2010), #R58 5 2 Inequalities in Funct i onal Analysis 2.1 Known inequalities For any (α 1 , . . . , α n ) ∈ R n , by (2) and the Cauchy-Schwarz ... cation: 46C05, 05A20, 60C05, 11T99 Abstract The main purpose of this paper is to show that many inequalities in functional analysis, probability theory and combinatorics are immediate...

Ngày tải lên: 08/08/2014, 12:22