Distribución de álgebras de Lie, MALCEV y evolución en clases de isotopismos

Abstract

This manuscript deals with distinct aspects of the theory of isotopisms of algebras. Particularly, we focus on isotopisms of Lie, Malcev and evolution algebras, for which this theory has not been enough studied in the literature. The manuscript is organized as follows. In Chapter 1 we expose a brief survey about the origin and development of the theory of isotopisms. This constitutes a first attempt in the literature to introduce this theory from a general point of view. Chapter 2 deals with those results in Computational Algebraic Geometry and Graph Theory that we use throughout the manuscript in order to compute the isotopism classes of each type of algebra under consideration in the subsequent chapters. We describe in particular a pair of graphs that enable us to define faithful functors between finite-dimensional algebras over finite fields and these graphs. The computation of isomorphism invariants of these graphs plays a remarkable role in the distribution of distinct families of algebras into isotopism and isomorphism classes. Some preliminary results are exposed in this regard, particularly on the distribution of partial-quasigroup rings over finite fields. Chapter 3 focuses on the distribution into isomorphism and isotopism classes of two families of Lie algebras: the set Pn;q of n-dimensional pre- filiform Lie algebras over the finite field Fq and the set Fn(K) of n-dimensional filiform Lie algebras over a base field K. Particularly, we prove the existence of n isotopism classes in Pn;q. We also introduce two new series of isotopism invariants that are used to determine the isotopism classes of the set Fn(K) for n ≤ 7 over algebraically closed fields and finite fields. Chapter 4 deals with distinct zero-dimensional radical ideals whose related algebraic sets are uniquely identified with the set Mn(K) of n-dimensional Malcev magma algebras over a finite field K. The computation of their reduced Gröbner bases, together with the classification of Lie algebras over finite fields given by De Graaf and Strade, enable us to determine the distribution of M3(K) and M4(K) not only into isomorphism classes, which is the usual criterion, but also into isotopism classes. Particularly, we prove the existence of four isotopism classes in M3(K) and eight isotopism classes in M4(K). Besides, we prove that every 3-dimensional Malcev algebra over any finite field and every 4-dimensional Malcev algebra over a finite field of characteristic distinct from two is isotopic to a Lie magma algebra. Finally, Chapter 5 deals with the set En(K) of n-dimensional evolution algebras over a field K, whose distribution into isotopism classes is uniquely related with mutations in non-Mendelian genetics. Particularly, we focus on the two-dimensional case, which is related to the asexual reproduction processes of diploid organisms. We prove that the set E2(K) is distributed into four isotopism classes, whatever the base field is, and we characterize its isomorphism classes.