144,653 research outputs found
Regular colored graphs of positive degree
Regular colored graphs are dual representations of pure colored D-dimensional
complexes. These graphs can be classified with respect to an integer, their
degree, much like maps are characterized by the genus. We analyse the structure
of regular colored graphs of fixed positive degree and perform their exact and
asymptotic enumeration. In particular we show that the generating function of
the family of graphs of fixed degree is an algebraic series with a positive
radius of convergence, independant of the degree. We describe the singular
behavior of this series near its dominant singularity, and use the results to
establish the double scaling limit of colored tensor models.Comment: Final version. Significant improvements made, main results unchange
Henneberg constructions and covers of cone-Laman graphs
We give Henneberg-type constructions for three families of sparse colored
graphs arising in the rigidity theory of periodic and other forced symmetric
frameworks. The proof method, which works with Laman-sparse finite covers of
colored graphs highlights the connection between these sparse colored families
and the well-studied matroidal (k, l)-sparse families.Comment: 14 pages, 2 figure
Topological Graph Polynomials in Colored Group Field Theory
In this paper we analyze the open Feynman graphs of the Colored Group Field
Theory introduced in [arXiv:0907.2582]. We define the boundary graph
\cG_{\partial} of an open graph \cG and prove it is a cellular complex.
Using this structure we generalize the topological (Bollobas-Riordan) Tutte
polynomials associated to (ribbon) graphs to topological polynomials adapted to
Colored Group Field Theory graphs in arbitrary dimension
A generalization of heterochromatic graphs
In 2006, Suzuki, and Akbari & Alipour independently presented a necessary and
sufficient condition for edge-colored graphs to have a heterochromatic spanning
tree, where a heterochromatic spanning tree is a spanning tree whose edges have
distinct colors. In this paper, we propose -chromatic graphs as a
generalization of heterochromatic graphs. An edge-colored graph is
-chromatic if each color appears on at most edges. We also
present a necessary and sufficient condition for edge-colored graphs to have an
-chromatic spanning forest with exactly components. Moreover, using this
criterion, we show that a -chromatic graph of order with
has an -chromatic spanning forest with exactly
() components if for any
color .Comment: 14 pages, 4 figure
Moduli spaces of colored graphs
We introduce moduli spaces of colored graphs, defined as spaces of
non-degenerate metrics on certain families of edge-colored graphs. Apart from
fixing the rank and number of legs these families are determined by various
conditions on the coloring of their graphs. The motivation for this is to study
Feynman integrals in quantum field theory using the combinatorial structure of
these moduli spaces. Here a family of graphs is specified by the allowed
Feynman diagrams in a particular quantum field theory such as (massive) scalar
fields or quantum electrodynamics. The resulting spaces are cell complexes with
a rich and interesting combinatorial structure. We treat some examples in
detail and discuss their topological properties, connectivity and homology
groups
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