Results 71 to 80 of about 14,274 (218)

Undecidability of polynomial inequalities in weighted graph homomorphism densities

open access: yesForum of Mathematics, Sigma
Many problems and conjectures in extremal combinatorics concern polynomial inequalities between homomorphism densities of graphs where we allow edges to have real weights.
Grigoriy Blekherman   +2 more
doaj   +1 more source

The isominwidth problem on the 2‐sphere

open access: yesMathematika, Volume 72, Issue 1, January 2026.
Abstract Pál's isominwidth theorem states that for a fixed minimal width, the regular triangle has minimal area. A spherical version of this theorem was proven by Bezdek and Blekherman, if the minimal width is at most π2$\tfrac{\pi }{2}$. If the width is greater than π2$\tfrac{\pi }{2}$, the regular triangle no longer minimizes the area at fixed ...
Ansgar Freyer, Ádám Sagmeister
wiley   +1 more source

Combinatorial theorems relative to a random set [PDF]

open access: yes, 2014
We describe recent advances in the study of random analogues of combinatorial theorems.Comment: 26 pages.
Conlon, David
core   +2 more sources

Geometric variational problems of statistical mechanics and of combinatorics

open access: yes, 2000
We present the geometric solutions of the various extremal problems of statistical mechanics and combinatorics. Together with the Wulff construction, which predicts the shape of the crystals, we discuss the construction which exhibits the shape of a ...
Alexander K.   +9 more
core   +2 more sources

Study of (p, q)‐Symmetric Starlike Functions of Order η

open access: yesJournal of Function Spaces, Volume 2026, Issue 1, 2026.
In the field of geometric function theory, we use the (p, q)‐differential operator in the complex unit disk to describe a novel class Sp,q∗∗η of symmetrical starlike functions of order η. Several interesting properties of functions belonging to the class Sp,q∗∗η are examined, such as growth, distortion, and convolution characteristics.
Imran Khan   +4 more
wiley   +1 more source

SPERNER THEOREMS FOR UNRELATED COPIES OF POSETS AND GENERATING DISTRIBUTIVE LATTICES

open access: yesUral Mathematical Journal
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

Maximum Shattering

open access: yesJournal of Combinatorial Designs, Volume 33, Issue 12, Page 456-470, December 2025.
ABSTRACT A family ℱ of subsets of [ n ] = { 1 , 2 , … , n } shatters a set A ⊆ [ n ] if for every A ′ ⊆ A, there is an F ∈ ℱ such that F ∩ A = A '. We develop a framework to analyze f ( n , k , d ), the maximum possible number of subsets of [ n ] of size d that can be shattered by a family of size k.
Noga Alon   +2 more
wiley   +1 more source

Extremal combinatorics, graph limits and computational complexity

open access: gold, 2016
This thesis is primarily focused on problems in extremal combinatorics, although we will also consider some questions of analytic and algorithmic nature. The d-dimensional hypercube is the graph with vertex set {0,1}d where two vertices are adjacent if they differ in exactly one coordinate.
Jonathan A. Noel
openalex   +3 more sources

Jordan Curves: Ramsey Approach and Topology

open access: yesMathematics
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

The Turán problem for hypergraphs of fixed size [PDF]

open access: yes, 2005
We obtain a general bound on the Turán density of a hypergraph in terms of the number of edges that it contains. If F is an r-uniform hypergraph with f edges we show that [pi](F) =3 and f->[infinity]
Keevash, Peter
core  

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