Finitely generated algebra
A **finitely generated algebra** is a specific type of algebraic structure that is built from a vector space over a field (often denoted \( K \)) by introducing a multiplication operation. The key aspect of a finitely generated algebra is that it can be constructed using a finite number of generators. More formally, let \( A \) be a vector space over a field \( K \).
Fitting ideal
In the context of algebraic geometry and commutative algebra, a **fitting ideal** is a specific type of ideal associated with a module over a ring. It captures information about the relations between elements of the module. For a finitely generated module \(M\) over a Noetherian ring \(R\), the Fitting ideals provide a way of understanding the structure of \(M\) in terms of its generators and relations.
Formally smooth map
In differential geometry and related fields, a **formally smooth map** generally refers to a type of map that behaves smoothly at a certain level, even if it may not be globally smooth in the traditional sense across its entire domain. The concept is often discussed in the context of algebraic geometry and singularity theory. To provide a clearer understanding: 1. **Smooth Maps**: A smooth map is typically a function between differentiable manifolds that is infinitely differentiable.
G-ring
The term "G-ring" can refer to several different concepts depending on the context, such as mathematics, chemistry, or other specialized fields. However, it is most commonly known in the context of algebra, specifically in ring theory. In mathematics, a **G-ring** typically refers to a **generalized ring**, which is a structure that generalizes the concept of a ring by relaxing some of the usual requirements.
GCD domain
In mathematics, a **GCD domain** (which stands for **Greatest Common Divisor domain**) is a type of integral domain that possesses certain properties regarding the divisibility of its elements. Specifically, an integral domain \( D \) is classified as a GCD domain if it satisfies the following conditions: 1. **Integral Domain:** \( D \) must be an integral domain (meaning it is a commutative ring with no zero divisors and has a multiplicative identity).
Geometrically regular ring
A geometrically regular ring is a concept that arises in algebraic geometry and commutative algebra. Specifically, it relates to geometric properties of the spectrum of a ring, particularly in regard to its points and their corresponding field extensions.
Glossary of commutative algebra
A glossary of commutative algebra is a collection of terms and definitions that are commonly used in the field of commutative algebra, which is a branch of mathematics that studies commutative rings, their ideals, and modules over those rings. Here are some key terms and concepts typically found in such a glossary: 1. **Ring**: A set equipped with two binary operations (addition and multiplication) that satisfy certain properties (associativity, distributivity, etc.).
Going up and going down
The phrases "going up" and "going down" can refer to various contexts depending on the subject matter. Here are a few interpretations: 1. **General Meaning**: - "Going up" often denotes an increase or upward movement, such as in prices, stock values, or in physical elevation (like climbing a hill). - "Going down" typically indicates a decrease or downward movement, such as falling prices, declining values, or descending physically.
Gorenstein ring
A **Gorenstein ring** is a type of commutative ring that has particularly nice homological properties. More formally, a Noetherian ring \( R \) is called Gorenstein if it satisfies the following equivalent conditions: 1. **Dualizing Complex**: The singularity category of \( R \) has a dualizing complex which is concentrated in non-negative degrees, and the homological dimension of the ring is finite.
Hahn series
A Hahn series is a formal power series that arises in the context of ordered groups and valuation theory. Specifically, it is used to describe a way to represent elements of certain fields, particularly in relation to ordered abelian groups.
Hausdorff completion
Hausdorff completion is a mathematical process used to construct a complete metric space from a given metric space that may not be complete. The idea is to extend the space in such a way that all Cauchy sequences converge within the new space. ### Overview of the Process: 1. **Metric Spaces and Completeness**: A metric space is a set equipped with a distance function (metric) that defines how far apart the points are.
Henselian ring
A Henselian ring is a type of commutative ring that satisfies a certain property related to the completeness of its valuation. More specifically, a ring \( R \) is called Henselian if it is equipped with a valuation \( v \) such that certain conditions hold, particularly that the ring is complete with respect to this valuation, and that certain polynomial equations behave like they do in a complete local field.
Hilbert's basis theorem
Hilbert's Basis Theorem is a fundamental result in algebra, particularly in the theory of rings and ideals. It states that if \( R \) is a Noetherian ring (meaning that every ideal in \( R \) is finitely generated), then any ideal in the polynomial ring \( R[x] \) (the ring of polynomials in one variable \( x \) with coefficients in \( R \)) is also finitely generated.
Hilbert's syzygy theorem
Hilbert's Syzygy Theorem is a fundamental result in the field of commutative algebra and algebraic geometry that concerns the relationships among generators of modules over polynomial rings. It provides a deeper insight into the structuring of polynomial ideals and their resolutions. In simple terms, the theorem addresses the projective resolutions of finitely generated modules over a polynomial ring.
The concepts of **Hilbert series** and **Hilbert polynomial** arise primarily in algebraic geometry and commutative algebra, particularly in the study of graded algebras and projective varieties. ### Hilbert Series The **Hilbert series** of a graded algebra (or a graded module) is a generating function that encodes the dimensions of its graded components.
Hilbert–Samuel function
The Hilbert–Samuel function is an important concept in commutative algebra and algebraic geometry, particularly in the study of the structure of space defined by ideals in rings and the geometry of schemes. It provides a way to measure the growth of the dimensions of the graded components of the quotient of a Noetherian ring by an ideal.
Hironaka decomposition
Hironaka decomposition is a concept in the context of algebraic geometry and singularity theory, specifically related to the resolution of singularities. The term is often associated with the work of Heisuke Hironaka, who is well-known for his theorem on the resolution of singularities in higher-dimensional spaces.
Hodge algebra
Hodge algebra is a concept in mathematics that arises in the study of Hodge theory, which is a field connecting algebraic topology, differential geometry, and algebraic geometry. Hodge theory is centered on the decomposition of differential forms on a smooth manifold and the study of their topological and geometric properties. More formally, a Hodge algebra typically refers to a certain type of graded algebra that arises in the context of Hodge theory, particularly when considering cohomology and the Hodge decomposition theorem.
Homological conjectures in commutative algebra refer to a collection of important and influential conjectures that relate to the behavior of modules over rings, particularly regarding their homological properties. These conjectures often involve investigating the relationships between various homological dimensions of modules (such as projective dimension, injective dimension, and global dimension) and their implications for ring theory and algebraic geometry.
I-adic topology
The \(I\)-adic topology is a concept from algebraic number theory and algebraic geometry that generalizes the notion of topology in the context of ideals in rings, specifically in relation to \(p\)-adic numbers.