In algebraic topology, the concept of the homotopy fiber is a key tool used to study maps between topological spaces. It can be considered as a generalization of the notion of the fiber in the context of fibration, and it helps to understand the homotopical properties of the map in question.
In algebraic topology, a mapping cone is a construction associated with a continuous map between two topological spaces. It is often used in the context of homology and cohomology theories, especially in the study of fiber sequences, and it is significant in understanding the relationships between different topological spaces.
N-skeleton
The term "N-skeleton" could refer to different concepts depending on the context, but it generally relates to certain structures in mathematics, particularly in geometry, topology, or combinatorics. Here are a few interpretations: 1. **Simplicial Complexes**: In the context of algebraic topology, the "N-skeleton" of a simplicial complex is the subcomplex consisting of all simplices of dimension less than or equal to \(N\).
Nonabelian algebraic topology is a branch of algebraic topology that focuses on the study of topological spaces and their properties using tools from nonabelian algebraic structures, particularly groups that do not necessarily commute. While traditional algebraic topology often deals with abelian groups (like homology and cohomology groups), nonabelian algebraic topology extends these ideas to settings where the relevant algebraic objects are nonabelian groups.
In topology, a "rose" (or "topologist's rose") is a specific type of topological space that is defined as the wedge sum of a finite number of circles. More formally, a rose with \( n \) petals is constructed by taking \( n \) copies of the unit circle \( S^1 \) and identifying all of their base points (typically the point at which they intersect the center of the rose).
Deligne's conjecture on Hochschild cohomology is a significant statement in the realm of algebraic geometry and homological algebra, particularly relating to the Hochschild cohomology of categories of coherent sheaves. Formulated by Pierre Deligne in the late 20th century, the conjecture concerns the relationship between the Hochschild cohomology of a smooth proper algebraic variety and the associated derived categories.
Derived algebraic geometry is a modern field of mathematics that extends classical algebraic geometry by incorporating tools and concepts from homotopy theory, derived categories, and categorical methods. It aims to refine the geometric and algebraic structures used to study schemes (the fundamental objects of algebraic geometry) by considering them in a more flexible and nuanced framework that can handle various kinds of singularities and complex relationships.
A "generalized map" can refer to different concepts depending on the context in which it is used. Here are a few interpretations based on various fields: 1. **Mathematics/Topology**: In topology, a generalized map might refer to a continuous function that extends the idea of mapping beyond traditional functions. For example, in homotopy theory, generalized maps could involve mappings between topological spaces that account for more abstract constructs like homotopies or morphisms.
In topology, "tautness" refers to a property of a mapping between two topological spaces, specifically in the context of a topological space being a **taut space**. A topological space is characterized as a taut space if it has certain conditions related to continuous mappings, particularly concerning their compactness and how they relate to other properties like being perfect, locally compact, or having specific kinds of bases.
3-folds
The term "3-folds" can refer to different concepts depending on the context in which it is used. Here are a few possible interpretations: 1. **Mathematics and Geometry**: In mathematics, "3-folds" often refers to three-dimensional objects or structures. In the context of algebraic geometry, a "3-fold" (or threefold) is a type of space that is defined by three dimensions.
Quadrics
"Quadrics" can refer to a few different concepts depending on the context. Here are a few possible interpretations: 1. **Mathematics**: In mathematics, specifically in geometry, quadrics are surfaces defined by second-degree polynomial equations in three-dimensional space. Common examples include ellipsoids, hyperboloids, and paraboloids.
An algebraic manifold, often referred to more generally as an algebraic variety when discussing its structure in algebraic geometry, is a fundamental concept that blends algebra and geometry. Here are the key aspects of algebraic manifolds: 1. **Definition**: An algebraic manifold is typically defined as a set of solutions to a system of polynomial equations. More formally, an algebraic variety is the set of points in a projective or affine space that satisfy these polynomial equations.
A Coble variety is a specific type of algebraic variety that arises in the study of certain geometric configurations, particularly in the context of algebraic geometry and the theory of Fano varieties. It is named after the mathematician William Coble. More specifically, a Coble variety can be defined as a particular type of three-dimensional projective variety that is defined as a smooth hypersurface in a projective space, often characterized by certain properties relating to its automorphisms and its geometric features.
The function field of an algebraic variety is a concept that arises in algebraic geometry. It can be thought of as the "field of rational functions" defined on the variety. Here’s a more detailed explanation: 1. **Algebraic Variety**: An algebraic variety is a geometric object that is defined as the solution set to a system of polynomial equations over a given field (typically the field of complex numbers or the rationals).
Linear algebraists are mathematicians or researchers who specialize in the field of linear algebra, a branch of mathematics concerned with vector spaces, linear mappings, and systems of linear equations. This area of study involves concepts such as vectors, matrices, determinants, eigenvalues, eigenvectors, and linear transformations. Linear algebraists may work on a variety of applications across different fields, including mathematics, engineering, computer science, physics, economics, and statistics.
Ernst Witt
Ernst Witt (1911–1991) was a prominent German mathematician known primarily for his work in algebra and group theory. He made significant contributions to the study of algebraic groups and related areas. Witt is perhaps best known for the development of the "Witt decomposition," which provides a way to decompose certain bilinear forms, and the "Witt hypothesis," related to the structure of certain types of algebraic groups.
Directed algebraic topology is a specialized area of mathematics that combines concepts from algebraic topology and category theory, focusing on the study of topological spaces and their properties in a "directed" manner. This field often involves the examination of spaces that possess some inherent directionality, such as those found in computer science, particularly in the study of directed networks, processes, and semantics of programming languages. In traditional algebraic topology, one often considers spaces and maps that are inherently undirected.
The Doomsday Conjecture is a theory proposed by mathematician John Horton Conway in the late 20th century. The conjecture relates to the calendar system, specifically predicting the date of significant events, including the likelihood of future catastrophic events based on the years of birth. Conway's Doomsday Conjecture asserts that certain dates of the year fall on the same day of the week, which can be used to determine the day of the week for any given date.
Eckmann–Hilton duality is a concept in algebraic topology and category theory that describes a relationship between certain algebraic structures, particularly in the context of homotopy theory and higher algebra. It emerges in the study of operads and algebraic models of spaces, particularly homotopy types and their associated algebraic invariants. The duality is expressed within the framework of category theory, particularly in the context of monoidal categories and homotopy coherent diagrams.
"Lehrbuch der Topologie" is a German phrase that translates to "Textbook of Topology." It typically refers to a comprehensive resource or textbook that covers various topics within the field of topology, a branch of mathematics concerned with the properties of space that are preserved under continuous transformations. There are several notable texts on topology, and one well-known book with a similar title is "Lehrbuch der Topologie" by Karl Heinrich Dähn.