Báo cáo toán hoc:" Rainbow matchings in r-partite r-graphs" pps
Báo cáo toán hoc:" Rainbow matchings in r-partite r-graphs" pps
... two of which sharing
an edge, h as an s-colored t-matching contained in its union.
In the case r = 2 the conjecture is that a set of t+1 disjoint t -matchings has a t -rainbow
matching. This is yet ... matching is said to be s -rainbow. If M has
an earmarking φ such that |Im(φ)| s we say also about M by itself that it is s -rainbow.
In this article we study matchings in r-parti...
Báo cáo toán học: "Rainbow matchings in properly edge colored graphs" pps
... is
called rainbow if its edges have distinct colors. Recently rainbow subgraphs have received
much attention, see the survey paper [8]. Here we are interested in rainbow matchings.
The study of rainbow ... then G has
a rainbow matchin g of size at least ⌊
2δ
3
⌋.
Keywords: rainbow matchings, properly colored graphs, triangle-free graphs
1 Introduction and notation
We use [3]...
Báo cáo toán học: "Perfect matchings in -regular graphs" potx
... perfect matchings of G satisfies
(d − 2)
n
n! ≤ M(G) ≤ (d +2)
n
n!.
Thus, the number of perfect matchings in any super (d, )-regular graph on 2n vertices
is close to the expected number of such matchings ... bound
follows by applying the Stirling approximation formula for factorials.
It is worth noting that since every -regular graph with density d and 2n vertices
contains, in ea...
Báo cáo toán học: "Maximum matchings in regular graphs of high girth" ppt
... The set of incidence vectors of the matchings of G have a
convex hull which is equal to the polytope containing all x ∈ R
E
which satisfy the following
the electronic journal of combinatorics ... matching (or one-factor) of G is a subgraph of G in which each vertex has
degree at most one. A basic question in combinatorial optimization is, “What is the size of a
maximum matching in a g...
Báo cáo toán học: "Heterochromatic matchings in edge-colored graphs" potx
... set of |T | distinct colors on some such set of |T | edges between S and distinct
vertices of T .
In [15], we obtained the following result concerning heterochromatic matchings in
colored bipartite ... The heterochromatic matchings in edge-
colored bipartite graphs, to appear in Ars Combinatoria, 2006.
[15] H. Li and G.H. Wang, Color degree and heterochromatic matchings in edg...
Báo cáo toán học: "Rainbow Matching in Edge-Colored Graphs" pot
... for K
4
or a graph obtained
from K
k+2
by removing a matching.
A survey on rainbow matchings and other rainbow subgraphs appears in [1]. Subgraphs
whose edges have distinct colors have also been ... n is odd, every proper n-edge-coloring of the complete bipartite
graph K
n,n
contains a rainbow perfect matching.
Wang and Li [4] studied rainbow matchings in arbitrary edge-colore...
Báo cáo toán học: "Perfect Matchings in Claw-free Cubic Graphs" pdf
... e
3
will be incident with
v
1
, v
2
, v
3
respectively.
Every ver tex in a claw-free cubic graph is in 1, 2, or 3 triangles. If a vertex is in 3
triangles, then the component containing the vertex ... permanents of certain (0, 1)-matrices. Nederl.
Aka d. Wetensch. Ind ag. Math., 41(1):83– 86, 1979.
the electronic journal of combinatorics 18 (2011), #P62 6
Perfect Matchings in Claw-f...
Báo cáo toán học: "Ear decompositions in combed graphs" pps
... t). A join pair (G, t) is a join covered pair if each edge of
G lies in a minimum t-join. Note that if T is a t-join in a join pair (G, t) and C is a
circuit with more than half its edges in T , ... circuit containing
P also contains all the other ears of X, including Q. By the inductive hypothesis, H has
a comb T
H
, equivalent to T ∩ EH, that has a balanced circuit containing e and...
Báo cáo toán học: "Lattice points in Minkowski sums" pps
... surfaces. Interdiscip. Inf. Sci., 12(2):93–107, 2006.
the electronic journal of combinatorics 15 (2008), #N11 5
Lattice points in Minkowski sums
Christian Haase, Benjamin Nill, Andreas Paffenholz
∗
Institut ... a (closed) strip R of lattice width one. The interior
of R intersects precisely two edges of Q, since the strip contains no lattice point in its
interior. Those two are the only edg...
Báo cáo toán học: "Semifields in Class F4" ppsx
... coefficients in F
q
2
, up to a
nonzero scalar. Again, since the point P
∞
is an o rdinary triple point for Γ and since C
3
is absolutely irreducible, we get that P
∞
is a simple point of either ... through the point P
∞
,
where C
n
has order n for some 1 ≤ n ≤ 5.
Case n = 1 Suppose first that there exists a line ℓ of P G(2, F) contained in Γ and
passing through the point P
∞
. Since ℓ is a...