On the closed Ramsey numbers R-cl(omega plus n, 3)

2021-11-01
In this paper, we contribute to the study of topological partition relations for pairs of countable ordinals and prove that, for all integers n ≥ 3, Rcl(ω + n, 3) ≥ ω2 · n + ω · (R(n, 3) − n) + n, Rcl(ω + n, 3) ≤ ω2 · n + ω · (R(2n − 3, 3) + 1) + 1, where Rcl(·, ·) and R(·, ·) denote the closed Ramsey numbers and the classical Ramsey numbers, respectively. We also establish the following asymptotically weaker upper bound: Rcl(ω + n, 3) ≤ ω2 · n + ω · (n2 − 4) + 1, eliminating the use of Ramsey numbers. These results improve the previously known upper and lower bounds.
ISRAEL JOURNAL OF MATHEMATICS

Suggestions

On a Fitting length conjecture without the coprimeness condition
Ercan, Gülin (Springer Science and Business Media LLC, 2012-08-01)
Let A be a finite nilpotent group acting fixed point freely by automorphisms on the finite solvable group G. It is conjectured that the Fitting length of G is bounded by the number of primes dividing the order of A, counted with multiplicities. The main result of this paper shows that the conjecture is true in the case where A is cyclic of order p (n) q, for prime numbers p and q coprime to 6 and G has abelian Sylow 2-subgroups.
On finite groups admitting a fixed point free abelian operator group whose order is a product of three primes
Mut Sağdıçoğlu, Öznur; Ercan, Gülin; Department of Mathematics (2009)
A long-standing conjecture states that if A is a finite group acting fixed point freely on a finite solvable group G of order coprime to jAj, then the Fitting length of G is bounded by the length of the longest chain of subgroups of A. If A is nilpotent, it is expected that the conjecture is true without the coprimeness condition. We prove that the conjecture without the coprimeness condition is true when A is a cyclic group whose order is a product of three primes which are coprime to 6 and the Sylow 2-sub...
On two applications of polynomials x^k-cx-d over finite fields and more
İrimağzı, Canberk; Özbudak, Ferruh (Springer, Cham, 2023-01-01)
For integers k∈[2,q−2] coprime to q−1 , we first bound the number of zeroes of the family of polynomials xk−cx−d∈Fq[x] where q=2n such that q−1 is a prime or q=3n such that (q−1)/2 is a prime. This gives us bounds on cross-correlation of a subfamily of Golomb Costas arrays. Next, we show that the zero set of xk−cx−d over Fq is a planar almost difference set in F∗q and hence for some set of pairs (c, d), they produce optical orthogonal codes with λ=1 . More generally, we give an algorithm to produ...
On the arithmetic complexity of Strassen-like matrix multiplications
Cenk, Murat (2017-05-01)
The Strassen algorithm for multiplying 2 x 2 matrices requires seven multiplications and 18 additions. The recursive use of this algorithm for matrices of dimension n yields a total arithmetic complexity of (7n(2.81) - 6n(2)) for n = 2(k). Winograd showed that using seven multiplications for this kind of matrix multiplication is optimal. Therefore, any algorithm for multiplying 2 x 2 matrices with seven multiplications is called a Strassen-like algorithm. Winograd also discovered an additively optimal Stras...
On diamond products ensuring irreducibility of the associated composed product
İrimağzi, Canberk; Özbudak, Ferruh (Informa UK Limited, 2023-2-16)
Let f and g be two irreducible polynomials of coprime degrees m and n whose zeroes lie in a set G⊆F¯¯¯q . Let ⋄ be a diamond product on G. We define the weaker cancelation property of ⋄ and show that it is sufficient to conclude that the composed product of f and g derived from ⋄ is an irreducible polynomial of degree mn. We also prove that a wide class of diamond products on finite fields satisfy the weaker cancelation property. These results extend the corresponding results of Brawley and Carlitz (1987...
Citation Formats
B. Kaya, “On the closed Ramsey numbers R-cl(omega plus n, 3),” ISRAEL JOURNAL OF MATHEMATICS, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/94934.