Thursday, September 17, 2020 2:30 pm
-
2:30 pm
EDT (GMT -04:00)
Title: Edge Deletion-Contraction in the Chromatic and Tutte Symmetric Functions
Speaker: | Logan Crew |
Affiliation: | University of Waterloo |
Zoom: | Contact Karen Yeats |
Abstract:
We
consider
symmetric
function
analogues
of
the
chromatic
and
Tutte
polynomials
on
graphs
whose
vertices
have
positive
integer
weights.
We
show
that
in
this
setting
these
functions
admit
edge
deletion-contraction
relations
akin
to
those
of
the
corresponding
polynomials,
and
we
use
these
relations
to
give
enumerative
and/or
inductive
proofs
of
properties
of
these
functions.
In
particular
we
note
that
the
Tutte
symmetric
function
in
this
form
is
related
to
a
family
of
vertex-weighted
graph
functions,
from
which
we
derive
a
recipe
theorem
and
a
spanning-tree
expansion.
This
is
joint
work
with
Sophie
Spirkl.