Galois cohomology and the subalgebras of the special linear algebra $\mathfrak{sl}_3(\mathbb{R})$

Abstract: We utilize Galois cohomology to classify the real subalgebras of the special linear algebra $\mathfrak{sl}_3(\mathbb{R})$, leveraging the established classification of complex subalgebras of $\mathfrak{sl}_3(\mathbb{C})$. Although a classification of the real subalgebras of $\mathfrak{sl}_3(\mathbb{R})$ already exists, our results and the methodology employed are significant for three key reasons. Firstly, it introduces a new approach to classifying real subalgebras of real semisimple Lie algebras, providing a framework for future work. Secondly, given the computational complexity and intricacy of such classifications, our verification of the previous classification through a different method provides a valuable contribution to the literature. Thirdly, subalgebras of semisimple Lie algebras have applications in both physics and applied mathematics; contributions to understanding the subalgebra structure of semisimple Lie algebras may enhance the implementation and comprehension of these applications.