Results 51 to 60 of about 125 (122)
A complex network perspective on brain disease
ABSTRACT If brain anatomy and dynamics have a complex network structure as it has become standard to posit, it is reasonable to assume that such a structure should play a key role not only in brain function but also in brain dysfunction. However, exactly how network structure is implicated in brain damage and whether at least some pathologies can be ...
David Papo, Javier M. Buldú
wiley +1 more source
A tropical approach to rigidity: Counting realisations of frameworks
Abstract A realisation of a graph in the plane as a bar‐joint framework is rigid if there are finitely many other realisations, up to isometries, with the same edge lengths. Each of these finitely many realisations can be seen as a solution to a system of quadratic equations prescribing the distances between pairs of points.
Oliver Clarke +6 more
wiley +1 more source
SPERNER THEOREMS FOR UNRELATED COPIES OF POSETS AND GENERATING DISTRIBUTIVE LATTICES
For a finite poset (partially ordered set) \(U\) and a natural number \(n\), let \(S(U,n)\) denote the largest number of pairwise unrelated copies of \(U\) in the powerset lattice (AKA subset lattice) of an \(n\)-element set.
Gábor Czédli
doaj +1 more source
Derangements in intransitive groups
Abstract Let G$G$ be a nontrivial permutation group of degree n$n$. If G$G$ is transitive, then a theorem of Jordan states that G$G$ has a derangement. Equivalently, a finite group is never the union of conjugates of a proper subgroup. If G$G$ is intransitive, then G$G$ may fail to have a derangement, and this can happen even if G$G$ has only two ...
David Ellis, Scott Harper
wiley +1 more source
Jordan Curves: Ramsey Approach and Topology
We develop a topological-combinatorial framework applying classical Ramsey theory to systems of arcs connecting points on Jordan curves and their higher-dimensional analogues.
Edward Bormashenko
doaj +1 more source
A Refined Graph Container Lemma and Applications to the Hard‐Core Model on Bipartite Expanders
ABSTRACT We establish a refined version of a graph container lemma due to Galvin and discuss several applications related to the hard‐core model on bipartite expander graphs. Given a graph G$$ G $$ and λ>0$$ \lambda >0 $$, the hard‐core model on G$$ G $$ at activity λ$$ \lambda $$ is the probability distribution μG,λ$$ {\mu}_{G,\lambda } $$ on ...
Matthew Jenssen +2 more
wiley +1 more source
Counting Independent Sets in Percolated Graphs via the Ising Model
ABSTRACT Given a graph G$$ G $$, we form a random subgraph Gp$$ {G}_p $$ by including each edge of G$$ G $$ independently with probability p$$ p $$. We provide an asymptotic expansion of the expected number of independent sets in random subgraphs of regular bipartite graphs satisfying certain vertex‐isoperimetric properties, extending the work of ...
Anna Geisler +3 more
wiley +1 more source
Random Fibonacci Words via Clone Schur Functions
We investigate positivity and probabilistic properties arising from the Young–Fibonacci lattice $\mathbb {YF}$ , a 1-differential poset on words composed of 1’s and 2’s (Fibonacci words) and graded by the sum of the digits.
Leonid Petrov, Jeanne Scott
doaj +1 more source
The Necessary Uniformity of Physical Probability
ABSTRACT According to contemporary consensus, physical probabilities may be “non‐uniform”: they need not correspond to a uniform measure over the space of physically possible worlds. Against consensus, I argue that only uniform probabilities connect robustly to long‐run frequencies.
Ezra Rubenstein
wiley +1 more source
Quantitative bounds in the polynomial Szemerédi theorem: the homogeneous case
Quantitative bounds in the polynomial Szemerédi theorem: the homogeneous case, Discrete Analysis 2017:5, 34 pp. Szemerédi's theorem, proved in 1975, asserts that for every positive integer $k$ and every $\delta>0$ there exists $n$ such that every subset
Sean Prendiville
doaj +1 more source

