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20132026
most citedHomomorphisms Are a Good Basis for Counting Small Subgraphs

81 citations · 134 across the 18 of their papers we have counts for

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18 papers · 1 filter

cs.CC2026

Counting Small Induced Subgraphs: Hardness of Symmetry-Based Properties

Radu Curticapean, Mingjun Liu

Jerrum and Meeks (TOCT, JCSS 2015) introduced the counting problems for fixed graph properties : Given an input graph and , count the -v…

cs.CC2026

Planar Perfect Matching Counting is as Hard as Determinants

Radu Curticapean, Jiaheng Wang

In the 1960s, Fisher, Kasteleyn and Temperley designed an ingenious algorithm for computing the partition function of the dimer model, or equivalently, for counting perfect matchin…

cs.CC2026

Beyond Bilinear Complexity: What Works and What Breaks with Many Modes?

Cornelius Brand, Radu Curticapean, Petteri Kaski +4

The complexity of bilinear maps (equivalently, of -mode tensors) has been studied extensively, most notably in the context of matrix multiplication. While circuit complexity and…

cs.CC2025

Which graph motif parameters count?

Markus Bläser, Radu Curticapean, Julian Dörfler +1

For a fixed graph H, the function #IndSub(H,*) maps graphs G to the count of induced H-copies in G; this function obviously "counts something" in that it has a combinatorial interp…

cs.CC2025

Monotone Bounded-Depth Complexity of Homomorphism Polynomials

C. S. Bhargav, Shiteng Chen, Radu Curticapean +1

For every fixed graph , it is known that homomorphism counts from and colorful -subgraph counts can be determined in time on -vertex input graphs , whe…

cs.CC2025

Counting Small Induced Subgraphs: Scorpions Are Easy but Not Trivial

Radu Curticapean, Simon Döring, Daniel Neuen

We consider the parameterized problem IndSub for fixed graph properties : Given a graph and an integer , this problem asks to count the number of induced -ver…

cs.CC2024

Counting Small Induced Subgraphs: Hardness via Fourier Analysis

Radu Curticapean, Daniel Neuen

For a fixed graph property and integer , consider the problem of counting the induced -vertex subgraphs satisfying in an input graph . This problem can be s…

cs.CC2023

Count on CFI graphs for #P-hardness

Radu Curticapean

Given graphs and , possibly with vertex-colors, a homomorphism is a function that preserves colors and edges. Many interesting counting problems (e.g., subg…

cs.CC2021★ 1 cited

Parameterizing the Permanent: Hardness for -minor-free graphs

Radu Curticapean, Mingji Xia

In the 1960s, statistical physicists discovered a fascinating algorithm for counting perfect matchings in planar graphs. Valiant later showed that the same problem is #P-hard for g…

cs.CC2021

Modular counting of subgraphs: Matchings, matching-splittable graphs, and paths

Radu Curticapean, Holger Dell, Thore Husfeldt

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

cs.CC2021

A full complexity dichotomy for immanant families

Radu Curticapean

Given an integer and an irreducible character of for some partition of , the immanant maps matri…

cs.CC2017

A Fixed-Parameter Perspective on #BIS

Radu Curticapean, Holger Dell, Fedor Fomin +2

The problem of (approximately) counting the independent sets of a bipartite graph (#BIS) is the canonical approximate counting problem that is complete in the intermediate complexi…

cs.CC2017

Counting edge-injective homomorphisms and matchings on restricted graph classes

Radu Curticapean, Holger Dell, Marc Roth

We consider the -hard problem of counting all matchings with exactly edges in a given input graph ; we prove that it remains -hard on graph…

cs.CC2016★ 1 cited

Counting matchings with k unmatched vertices in planar graphs

Radu Curticapean

We consider the problem of counting matchings in planar graphs. While perfect matchings in planar graphs can be counted by a classical polynomial-time algorithm, the problem of cou…

cs.CC2015

Parity Separation: A Scientifically Proven Method for Permanent Weight Loss

Radu Curticapean

Given an edge-weighted graph G, let PerfMatch(G) denote the weighted sum over all perfect matchings M in G, weighting each matching M by the product of weights of edges in M. If G…

cs.CC2015★ 4 cited

Parameterizing the Permanent: Genus, Apices, Minors, Evaluation mod 2^k

Radu Curticapean, Mingji Xia

We identify and study relevant structural parameters for the problem PerfMatch of counting perfect matchings in a given input graph . These generalize the well-known tractable p…

cs.CC2015

Block Interpolation: A Framework for Tight Exponential-Time Counting Complexity

Radu Curticapean

We devise a framework for proving tight lower bounds under the counting exponential-time hypothesis #ETH introduced by Dell et al. (ACM Transactions on Algorithms, 2014). Our frame…

cs.CC2014★ 11 cited

Complexity of counting subgraphs: only the boundedness of the vertex-cover number counts

Radu Curticapean, Dániel Marx

For a class of graphs, #Sub is the counting problem that, given a graph and an arbitrary graph , asks for the number of subgraphs…