Displaying similar documents to “On isometries of the symmetric space P₁(3,ℝ)”

Construction of symmetric Hadamard matrices of order 4v for v = 47, 73, 113

N. A. Balonin, D. Ž. Ðokovic, D. A. Karbovskiy (2018)

Special Matrices

Similarity:

We continue our systematic search for symmetric Hadamard matrices based on the so called propus construction. In a previous paper this search covered the orders 4v with odd v ≤ 41. In this paper we cover the cases v = 43, 45, 47, 49, 51. The odd integers v < 120 for which no symmetric Hadamard matrices of order 4v are known are the following: 47, 59, 65, 67, 73, 81, 89, 93, 101, 103, 107, 109, 113, 119. By using the propus construction, we found several symmetric Hadamard matrices...

Symmetric Hadamard matrices of order 116 and 172 exist

Olivia Di Matteo, Dragomir Ž. Ðoković, Ilias S. Kotsireas (2015)

Special Matrices

Similarity:

We construct new symmetric Hadamard matrices of orders 92, 116, and 172. While the existence of those of order 92 was known since 1978, the orders 116 and 172 are new. Our construction is based on a recent new combinatorial array (GP array) discovered by N. A. Balonin and J. Seberry. For order 116 we used an adaptation of an algorithm for parallel collision search. The adaptation pertains to the modification of some aspects of the algorithm to make it suitable to solve a 3-way matching...

Generalized symmetric spaces and minimal models

Anna Dumańska-Małyszko, Zofia Stępień, Aleksy Tralle (1996)

Annales Polonici Mathematici

Similarity:

We prove that any compact simply connected manifold carrying a structure of Riemannian 3- or 4-symmetric space is formal in the sense of Sullivan. This result generalizes Sullivan's classical theorem on the formality of symmetric spaces, but the proof is of a different nature, since for generalized symmetric spaces techniques based on the Hodge theory do not work. We use the Thomas theory of minimal models of fibrations and the classification of 3- and 4-symmetric spaces.

On the symmetric continuity

Jaskuła, Janusz, Szkopińska, Bożena (2015-12-15T14:49:03Z)

Acta Universitatis Lodziensis. Folia Mathematica

Similarity:

E-symmetric numbers

Gang Yu (2005)

Colloquium Mathematicae

Similarity:

A positive integer n is called E-symmetric if there exists a positive integer m such that |m-n| = (ϕ(m),ϕ(n)), and n is called E-asymmetric if it is not E-symmetric. We show that there are infinitely many E-symmetric and E-asymmetric primes.

Selfadjoint operator matrices with finite rows

Jan Janas, Jan Stochel (1997)

Annales Polonici Mathematici

Similarity:

A generalization of the Carleman criterion for selfadjointness of Jacobi matrices to the case of symmetric matrices with finite rows is established. In particular, a new proof of the Carleman criterion is found. An extension of Jørgensen's criterion for selfadjointness of symmetric operators with "almost invariant" subspaces is obtained. Some applications to hyponormal weighted shifts are given.