Реализуемость прямых произведений групп преобразований изометриями метрических пространств

Введено конструкцію s-добутку рівномірно дискретних метричних просторів скінченного діаметра. Показано, що з реалізовності двох груп перетворень ізометріями рівномірно дискретних метричних просторів скінченного діаметра випливає також реалізовність прямого добутку цих груп ізометріями рівномірно дискретного простору скінченного діаметра.The s-product of uniformly bounded discrete metric spaces with finite diameters is introduced. It is shown that if two transformation groups have representations as isometry groups of uniformly discrete metric spaces of finite diameters, then the direct product of these transformation groups will also have a uniformly discrete metric space of finite diameter, for which it is isomorphic to its isometry group

Matrix characterization of symmetry groups of boolean functions

We studies symmetry groups of boolean functions and construct new way of description of this problem in matrices language. Some theorems about constructions of symmetry groups with using matrices are presented. Some properties of this approach are given

Paley Graphs and Their Generalizations

To construct a Paley graph, we fix a finite field and consider its elements as vertices of the Paley graph. Two vertices are connected by an edge if their difference is a square in the field. We will study some important properties of the Paley graphs. In particular, we will show that the Paley graphs are connected, symmetric, and self-complementary. Also we will show that the Paley graph of order q is (q-1)/2 -regular, and every two adjacent vertices have (q-5)/4 common neighbors, and every two non-adjacent vertices have q-1/4 common neighbors, which means that the Paley graphs are strongly regular with parameters(q,q-1/2,q-5/4, q-1/4). Paley graphs are generalized by many mathematicians. In the first section of Chapter 3 we will see three examples of these generalizations and some of their basic properties. In the second section of Chapter 3 we will define a new generalization of the Paley graphs, in which pairs of elements of a finite field are connected by an edge if and only if there difference belongs to the m-th power of the multiplicative group of the field, for any odd integer m > 1, and we call them the m-Paley graphs. In the third section we will show that the m-Paley graph of order q is complete if and only if gcd(m, q - 1) = 1 and when d = gcd(m, q - 1) > 1, the m-Paley graph is q-1/d -regular. Also we will prove that the m-Paley graphs are symmetric but not self-complementary. We will show also that the m-Paley graphs of prime order are connected but the m-Paley graphs of order p^n, n > 1 are not necessary connected, for example they are disconnected if gcd(m, p^n - 1) =(p^n-1)/ 2.Comment: Master Thesi

Self-Complementary Arc-Transitive Graphs and Their Imposters

This thesis explores two infinite families of self-complementary arc-transitive graphs: the familiar Paley graphs and the newly discovered Peisert graphs. After studying both families, we examine a result of Peisert which proves the Paley and Peisert graphs are the only self-complementary arc transitive graphs other than one exceptional graph. Then we consider other families of graphs which share many properties with the Paley and Peisert graphs. In particular, we construct an infinite family of self-complementary strongly regular graphs from affine planes. We also investigate the pseudo-Paley graphs of Weng, Qiu, Wang, and Xiang. Finally, we prove a lower bound on the number of maximal cliques of certain pseudo-Paley graphs, thereby distinguishing them from Paley graphs of the same order