This book collects the extended abstracts of the accepted contributions to EuroComb21. A similar book is published at every edition of EuroComb (every two years since 2001) collecting the most recent advances in combinatorics, graph theory, and related areas. It has a wide audience in the areas, and the papers are used and referenced broadly.

Is published at every edition of EuroComb which is one of the leading conferences in the area worldwide Presents the most recent achievements in this conference Collects the extended abstracts of the accepted contributions to EuroComb21

Inhalt

Size of local finite field Kakeya sets.- Coloring of Graphs Avoiding Bicolored Paths of a Fixed Length.- Nested cycles with no geometric crossings.- Cut vertices in random planar graphs.- Extremal density for sparse minors and subdivisions.- Enumerating descents on quasi-Stirling permutations and plane trees.- Hamiltonicity of randomly perturbed graphs.- The largest hole in sparse random graphs.- On 13-Crossing-Critical Graphs with Arbitrarily Large Degrees.- Local convergence of random planar graphs.- Some results on the Laplacian spectra of token graphs.- On the Number of Compositions of Two Polycubes.- Halin's end degree conjecture.- Coloring Circle Arrangements: New 4-Chromatic Planar Graphs.- A Short Proof of EulerPoincaré Formula.- Approximate MDS Property of Linear Codes.- A SAT attack on higher dimensional Erd\H{o}s--Szekeres numbers.- Improved bounds on the cop number of a graph drawn on a surface.- Stability of Berge-hypergraphs]{Stability of extremal connected hypergraphs avoiding Berge-paths, (extended abstract).- On tangencies among planar curves]{On tangencies among planar curves with an application to coloring L-shapes.- Semi-random process without replacement.- The intersection spectrum of 3-chromatic intersecting hypergraphs.- On ordered Ramsey numbers of tripartite 3-uniform hypergraphs.- Hypergraphs with minimum positive uniform Turan density.- Rainbow cliques in randomly perturbed dense graphs.- Universal singular exponents in catalytic variable equations.- The expected number of perfect matchings in cubic planar graphs.- Gallai-Ramsey number for complete graphs.- On the dichromatic number of surfaces.- Supersaturation, counting, and randomness inforbidden subposet problems.- Path decompositions of tournaments.- Sorting by shuffling methods and a queue.- Circular coloring of signed bipartite planar graphs.- Results on the Graceful Game and Range-Relaxed Graceful Game.- New bounds on the modularity of Johnson graphs and random subgraphs of Johnson graphs.- On Bipartite Sum Basic Equilibria.- Characterization and enumeration of preimages under the Queuesort algorithm.- On off-diagonal ordered Ramsey numbers of nested matchings.- Bounds on half graph orders in powers of sparse graphs.- The homotopy type of the independence complex of graphs with no induced cycles of length divisible by $3$.- The Maximum Number of Paths of Length Three in a Planar Graph.- Strongly Pfaffian Graphs.- Strong modeling limits of graphs with bounded tree-width.- Loose cores and cycles in random hypergraphs (extended abstract).- Building a larger class of graphs for efficient reconfiguration of vertex colouring.- A refinement of Cauchy-Schwarz complexity, with applications (extended abstract).- The Ising antiferromagnet in the replica symmetric phase.- A simple (2+\epsilon)-approximation algorithm for Split Vertex Deletion.- On graphs without an induced path on 5 vertices and without an induced dart or kite.- Constant congestion brambles in directedgraphs.- Component behaviour of random bipartite graphs.- Maximising line subgraphs of diameter at most $t$.- Unavoidable hypergraphs.- $2$-distance $(\Delta+1)$-coloring of sparse graphs using the potential method.- Graphs where Search Methods are Indistinguishable.- Discrete Helly-type theorems for pseudohalfplanes.- Cycles of Many Lengths in Hamiltonian Graphs.- Maximal $k$-wise $\ell$-divisible set families are atomic.- A Trivariate Dichromate Polynomial for Digraphs.- Schur's Theorem for randomly perturbed sets.- Unit Disk Visibility Graphs.- Waiter-Client Games on Randomly Perturbed Graphs.- Vector Choosability in Bipartite Graphs.- Tight bounds on the expected number of holes in random point sets.- The game of Toucher and Isolator.- Hermitian rank-metric codes.- The Flat Wall Theorem for Bipartite Graphs with Perfect Matchings.- Big Ramsey degrees and forbidden cycles.- The Ramsey number for 4-uniform tight cycles.- Chip-firing on the complete split graph: Motzkin words and tiered parking functions.- Long shortest cycle covers in cubic graphs.- Powers of Hamilton cycles of high discrepancy are unavoidable.- Low Diameter Algebraic Graphs.- The fractional chromatic number of double cones over graphs.- Complexity of $3+1/m$-coloring $Pt$-free graphs.- Shattering Threshold for the Coloring Problem of a Random Hypergraph.- Integer covering problems and max-norm Ramsey theorems.- Unit disks hypergraphs are three-colorable.- Characterization of FS-double Squares Ending with Two Distinct Squares.- On asymmetric hypergraphs.- On Multicolour Ramsey Numbers and Subset-Colouring of Hypergraphs.- Max Cuts in Triangle-free Graphs.- On the cycle rank conjecture about metric dimension and zero forcing number in graphs.- Tight bounds for powers of Hamilton cycles in tournaments.- On sufficient conditions for Hamiltonicity in dense graphs.- On the maximum number of weakly-rainbow-free edge-colorings.- Degree conditions for tight Hamilton cycles.- An Approximate Structure Theorem for Small Sumsets.- Classification of Local Problems on Paths from the Perspective of Descriptive Combinatorics.- On the enumeration of plane bipolar posets and transversal structures.- The characterization of graphs whose sandpile group has fixed number of generators.- Kissing number in non-Euclidean spaces of constant sectional curvature.- Decomposing cubic graphs with cyclic connectivity 5.- Dirac-type conditions for spanning bounded-degree hypertrees.- Outer 1-string graphs of girth at least five are 3-colorable.- The rainbow Turan number of even cycles.- Trees with few leaves in tournaments.- Uncommon systems of equations.- Exchange properties of finite set-systems.- On a question of Vera T. Sós about size forcing of graphons (extended abstract).- On Deeply Critical Oriented Cliques.- Big Ramsey degrees of the generic partial order.- The square of a Hamilton cycle in randomly perturbed graphs.- On extremal problems concerning the traces of sets.- The chromatic number of signedgraphs with bounded maximum average degree.- Maker--Breaker games with constraints.- Parallelisms of PG(3,5) with an automorphism group of order 25.- On Alternation, VC-dimension and k-fold Union of Sets.- Weak components of the directed conguration model.- Decomposing and Colouring Locally Out-Transitive Oriented Graphs.- Ramsey expansions of 3-hypertournaments.- Path decompositions of random directed graphs.- Large multipartite subgraphs in H-free graphs.- Kempe changes in bounded treewidth graphs.- No Selection Lemma for Empty Triangles.- The mod $k$ chromatic index of random graphs.- Constructions of betweenness-uniform graphs from trees.- On the homomorphism order of oriented paths and trees.- On chromatic number of (n, m)-graphs.- On a problem of Füredi and Griggs.- Gallai's path decomposition for planar graphs.- Tuza's Conjecture for threshold graphs.- Covering three-tori with cubes.- New bounds on $k$-geodetic digraphs and mixed graphs.- Counting $Ck$-free orientationsof $G(n,p)$.- Counting Circuit Double Covers.- Oriented graphs with lower orientation Ramsey thresholds.- Random 2-cell embeddings of multistars.- Cycle saturation in random graphs.- On the maximum cut in sparse random hypergraphs.- Asymptotics for connected graphs and irreducible tournament.- Interval representation of balanced separators in graphs avoiding a minor.- Lines in the Manhattan plane.- A …