We introduce graph motif parameters, a class of graph parameters that depend only on the
frequencies of constant-size induced subgraphs. Classical works by Lovász show that many …

In this paper, we design efficient algorithms to approximately count the number of edges of a
given k-hypergraph, and to sample an approximately uniform random edge. The hypergraph …

Given a graph property $\Phi $, we consider the problem $\mathtt {EdgeSub}(\Phi) $, where
the input is a pair of a graph $ G $ and a positive integer $ k $, and the task is to decide …

We systematically investigate the complexity of counting subgraph patterns modulo fixed
integers. For example, it is known that the parity of the number of $ k $-matchings can be …

In this paper, we show how one may (efficiently) construct two types of extremal
combinatorial objects whose existence was previously conjectural.• Panchromatic Graphs …

We study the complexity of query evaluation of SPARQL queries. We focus on the
fundamental fragment of well-designed SPARQL restricted to the AND, OPTIONAL and …

A homomorphism between graphs H and G, possibly with vertex-colors, is a function f: V
(ℋ)→ V (G) that preserves colors and edges. Many interesting graph parameters are finite …

Despite much work within the last decade on foundational properties of SPARQL-the
standard query language for RDF data-rather little is known about the exact limits of …