Báo cáo toán học: "An improved bound on the minimal number of edges in color-critical graphs" pot
Báo cáo toán học: "An improved bound on the minimal number of edges in color-critical graphs" pot
... (1)
The second ingredient of our proof is the following result of Stiebitz.
Lemma 3 ([5]) Let G be a k-critical graph containing at least one vertex of degree k − 1.
Then the number of connected ... that
n
L
> 0.
An improved bound on the minimal number of edges in
color-critical graphs
Michael Krivelevich
∗
School of Mathematics,
Institute for Advanced...
Báo cáo toán học: "A new bound on the domination number of graphs with minimum degree two" docx
... contain a triangle that contains two vertices of
degree 2 in the resulting graph. Continuing this process, we would reach a contradiction
since the 4-cycle, which is the only graph in F
4
, contains ... = V .) The
domination number of G, denoted by γ(G), is the minimum cardinality of a dominating
set. A dominating set of G of cardinality γ(G) is called a γ(G)-set.
If...
Báo cáo toán học: "Sharp lower bound for the total number of matchings of tricyclic graphs" doc
... pendants having minimal Hosoya index. In [21] Li et al. characterized unicyclic
graphs with minimal, second -minimal, third -minimal, fourth -minimal, fifth -minimal a nd
sixth -minimal Hosoya index. Recently, ... gave the sharp lower bound on the
Hosoya index of unicyclic gra phs. In [15], Hua determined the minimum of the Hosoya
index within a class of unicyclic gr...
Báo cáo toán học: "An addition theorem on the cyclic group Zpαqβ" pptx
... denote the maximal multiplicity of the terms of S.
In 1961, Erd˝os-Ginzburg-Ziv [1] proved the following theorem.
EGZ Theorem If S is a sequence of elements from Z
n
of length 2n− 1, then 0 ∈
n
S.
The ... do it. Therefore
k
j=1
a
(1)
j
∈ A
1
+ A
2
+ ···+ A
k
,
the electronic journal of combinatorics 13 (2006), #N9 2
An addition theorem on the cyclic group Z
p
α
q...
Báo cáo toán học: "An improved tableau criterion for Bruhat order" ppt
... i ∈ E.
Proof. For I = this is Lemma 3.6 of Deodhar [D, p. 195]. His result takes care of the
⇒ direction. His proof of the ⇐ direction is by induction on (y). The induction step (the
laborious ... characterization of Bruhat order (in the geometric version) was found by Ehres-
mann [E] to describe cell decompositions of flag manifolds. The construction (but not the
ch...
Báo cáo hóa học: " An Improved Algorithm for the Piecewise-Smooth Mumford and Shah Model in Image Segmentation" docx
... function. Instead of using the zero level of
a funct ion to represent the interface between subdomains,
the interface is represented implicitly by the discontinuities
of a level set function. Tsai ... by calculating
the union of u
+
on {φ>0} and u
−
on {φ<0}.Basedon
this idea, one can directly develop the level set function φ on
the diffused image instead of...
Báo cáo toán học: "An Asymptotic Expansion for the Number of Permutations with a Certain Number of Inversions" docx
... paper.
An Asymptotic Expansion for the Number of
Permutations with a Certain Number of Inversions
Lane Clark
Department of Mathematics
Southern Illinois University Carbondale
Carbondale, IL 62901-4408 ... expansion of the integral. Among
the consequences, we have a complete asymptotic expansion for b(n, k)/n!fora
range of k including the maximum of the b(n, k)/n!.
AM...
Báo cáo toán học: "NEW UPPER BOUNDS ON THE ORDER OF CAGES1" pps
... constructed in [9] by F¨uredi, Seress, and the authors.
The fact that the orders of these constructions actually meet the upper bound in
(2) for q odd follows from [13]. The constructions we introduce ... construction of combinatorial
schemes and their application to the design of expanders and concentrators,
Journal of Problems of Information Transmission (1988),...
Báo cáo toán học: "A LOWER BOUND FOR THE NUMBER OF EDGES IN A GRAPH CONTAINING NO TWO CYCLES OF THE SAME LENGTH" pptx
... denote the number of vertices, and (G) denote the number of edges. In this
paper, we construct a graph G having no two cycles with the same length which leads to
the following result.
Theorem. ... shall show
that there exists a graph G on n vertices with n +32t − 1 edges such that all cycles in G
have distinct lengths.
Now we construct the graph G which consists o...
Báo cáo toán học: "An asymptotic Result for the Path Partition Conjecture" pps
... directed
version of the PPC. In [3] the PPC is stated in the language of the theory of hereditary
properties of graphs. It is also mentioned in [5]. Results on the PPC and its relationship
with other conjectures ... Main Results
In this section we state our two main theorems, together with the main lemmas and the
partition strategy used in the proofs. The...
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