In geometry, a "slab" typically refers to a three-dimensional shape that is essentially a thick, flat object bounded by two parallel surfaces. This can be visualized as a rectangular prism with very small height relative to its length and width, resembling a sheet or a plate. In a more formal mathematical context, particularly in the study of convex geometry, a slab can be defined by two parallel hyperplanes in higher-dimensional spaces.

De Rham cohomology is a mathematical concept from the field of differential geometry and algebraic topology that studies the topology of smooth manifolds using differential forms. It provides a bridge between analysis and topology by utilizing the properties of differential forms and their relationships through the exterior derivative. ### Key Concepts 1. **Differentiable Manifolds**: A differentiable manifold is a topological space that is locally similar to Euclidean space and has a well-defined notion of differentiability.

Elliptic cohomology is a branch of algebraic topology that generalizes classical cohomology theories using the framework of elliptic curves and modular forms. It is an advanced topic that blends ideas from algebraic geometry, number theory, and homotopy theory. ### Key Features 1.

Lie algebra cohomology is a mathematical concept that arises in the study of Lie algebras, which are algebraic structures used extensively in mathematics and physics to describe symmetries and conservation laws. Cohomology, in this context, refers to a homological algebra framework that helps in analyzing the structure and properties of Lie algebras.

In mathematics, particularly in the field of abstract algebra and category theory, a **category of groups** is a concept that arises from the framework of category theory, which is a branch of mathematics that deals with objects and morphisms (arrows) between them. ### Basic Definitions 1. **Category**: A category consists of: - A collection of objects. - A collection of morphisms (arrows) between those objects, which can be thought of as structure-preserving functions.

Emily Riehl is a mathematician known for her contributions to category theory, homotopy theory, and algebraic topology. She is an associate professor at Johns Hopkins University and has published several research papers in her areas of expertise. Riehl has also been involved in mathematical education, producing resources aimed at improving the teaching and understanding of mathematics, particularly in higher education. She is recognized for her work in making advanced mathematical concepts more accessible.

In mathematics, particularly in the field of algebraic geometry and homological algebra, a **derived category** is a concept that allows one to work with complexes of objects (such as sheaves, abelian groups, or modules) in a way that takes into account their morphisms up to homotopy. Derived categories provide a framework for studying how complex objects relate to one another and for performing calculations in a more flexible manner than is possible in the traditional context of abelian categories.

Michael Shulman is a mathematician known for his work in the fields of algebra, category theory, and type theory. He has made contributions to the study of homotopy theory, higher categories, and the connections between mathematics and computer science, particularly in the context of programming languages and formal systems. Shulman has also been involved in research that bridges the gap between abstract mathematical theory and practical computational applications.

Valeria de Paiva is a Brazilian mathematician known for her work in the field of type theory, particularly in the context of computer science and programming languages. She has made significant contributions to the development of mathematical frameworks that inform type systems in software, which are critical for ensuring code correctness and safety. Additionally, Valeria de Paiva has been involved in research related to category theory and its applications in functional programming. She is also noted for her engagement in teaching and collaboration within the academic community.

A **quasigroup** is an algebraic structure that consists of a set equipped with a binary operation that satisfies a specific condition related to the existence of solutions to equations. More formally, a quasigroup is defined by the following properties: 1. **Set and Operation**: A quasigroup is a set \( Q \) along with a binary operation \( * \) (often referred to as "multiplication").

The Pincherle derivative is a concept from the field of functional analysis, particularly in the study of linear operators and spaces of functions. It is a type of derivative that generalizes the traditional notion of differentiation for certain classes of functions, especially those that can be represented as power series or polynomials in some functional spaces.

In group theory, a branch of abstract algebra, an essential subgroup is a specific type of subgroup that has particular relevance in the context of group actions and the structure of groups. A subgroup \( H \) of a group \( G \) is said to be essential in \( G \) if it intersects every nontrivial subgroup of \( G \).

A Prüfer group, also known as a Prüfer \(p\)-group, is a type of abelian group that can be defined for a prime number \(p\).

In mathematics, "E7" typically refers to one of the exceptional Lie groups, which are important in various fields, including algebra, geometry, and theoretical physics. Specifically, E7 is a complex, simple Lie group of rank 7 that can be understood in terms of its root system and algebraic structure.

In the context of algebraic groups and group theory, a **Borel subgroup** is a specific type of subgroup that is particularly important in the study of linear algebraic groups. Here are the key points regarding Borel subgroups: 1. **Definition**: A Borel subgroup of an algebraic group \( G \) is a maximal connected solvable subgroup of \( G \). This means that it cannot be contained in any larger connected solvable subgroup of \( G \).

Geometric Invariant Theory (GIT) is a branch of algebraic geometry that studies the action of group actions on algebraic varieties, particularly focusing on understanding the properties of orbits and established notions of stability. It was developed primarily in the 1950s by mathematician David Mumford, building on ideas from group theory, algebraic geometry, and representation theory.

The Jacobson–Morozov theorem is a result in the representation theory of Lie algebras, specifically concerning the existence of certain embeddings of semisimple Lie algebras.

Kostant polynomials are a class of polynomials that arise in the study of Lie algebras, representation theory, and several areas of algebraic geometry. They were introduced by Bertram Kostant in his work on the structure of semisimple Lie algebras and their representations. In particular, Kostant polynomials are closely associated with the weights of representations of a Lie algebra and its root system.

Weyl modules are a family of representations associated with Lie algebras and are particularly important in the representation theory of semisimple Lie algebras. They are named after Hermann Weyl, who made significant contributions to the field of representation theory. ### Definition For a semisimple Lie algebra \(\mathfrak{g}\) over a field, a Weyl module \(V_\lambda\) is constructed for a given dominant integral weight \(\lambda\).