Surgery theory is a branch of geometric topology, which focuses on the study of manifolds and their properties by performing a kind of operation called surgery. The central idea of surgery theory is to manipulate manifold structures in a controlled way to produce new manifolds from existing ones. This can involve various operations, such as adding or removing handles, which change the topology of manifolds in a systematic manner.
H-space
In the context of topology, an **H-space** is a type of space that has a continuous multiplication that satisfies certain properties resembling those of algebraic structures.
Homeotopy
Homeotopy refers to a concept in topology, a branch of mathematics that deals with properties of space that are preserved under continuous transformations. Specifically, the term "homeotopy" is often used interchangeably with "homotopy," which describes a way of continuously transforming one continuous function into another.
A homology manifold is a concept in algebraic topology, which generalizes some properties of manifolds in the context of homology theory. Specifically, a topological space is called a homology manifold if it satisfies certain homological conditions that are analogous to those of a manifold.
The 1st meridian west, also known as the Prime Meridian West, is a line of longitude that is located 1 degree west of the Prime Meridian, which is defined as 0 degrees longitude. The Prime Meridian runs through Greenwich, London, and serves as the reference point for defining other longitudes. The 1st meridian west is part of the system of geographic coordinates used to specify locations on Earth.
Garnir relations refer to a specific set of algebraic identities that arise in the context of representation theory and the study of certain mathematical structures, particularly in relation to symmetric groups and permutation representations. Named after the mathematician Jean Garnir, these relations are particularly important in the study of the modular representation theory of symmetric groups and their related structures.
Cubic curves are mathematical curves represented by polynomial equations of degree three. In general, a cubic curve can be expressed in the form: \[ y = ax^3 + bx^2 + cx + d \] where \( a \), \( b \), \( c \), and \( d \) are constants, and \( a \neq 0 \).
Bifolium
A bifolium is a term used in bookbinding and manuscript studies to refer to a single sheet of paper or parchment that is folded in half to create two leaves (or four pages). The word "bifolium" comes from Latin roots: "bi-" meaning two and "folium" meaning leaf.
A Cassini oval is a type of mathematical curve defined as the locus of points for which the product of the distances to two fixed points (called foci) is constant. Unlike an ellipse, where the sum of the distances to the two foci is constant, in a Cassini oval the relationship involves multiplication.
The Chiral Potts model is a mathematical model used in statistical mechanics, particularly in the study of phase transitions and critical phenomena. It is a generalization of the Potts model, which itself extends the Ising model, and it incorporates chirality, a property that distinguishes between left-handed and right-handed configurations.
A Fermat curve is a type of algebraic curve defined by the equation: \[ x^n + y^n = z^n \] for a positive integer \(n \). The most well-known case of Fermat curves is when \( n = 2 \), which gives the equation of a circle: \[ x^2 + y^2 = z^2.
A hyperelliptic curve is a type of algebraic curve that generalizes the properties of elliptic curves. Specifically, it is defined over a field (often the field of complex numbers, rational numbers, or finite fields) and can be described by a specific kind of equation.
In topology, "collapse" generally refers to a process in which a space is transformed into a simpler space by identifying or merging certain points. More formally, it often involves a kind of equivalence relation on a topological space that leads to a new space, typically by collapsing a subspace of points into a single point or by collapsing all points in a certain way. One specific example of collapsing is the creation of a quotient space.
In mathematics, particularly in topology and algebraic geometry, the term "genus" has several related but distinct meanings depending on the context. Here are some of the most common interpretations: 1. **Genus in Topology**: The genus of a topological surface refers to the number of "holes" or "handles" in the surface.
A homogeneous variety is a type of algebraic variety that exhibits a particular structure of symmetry. More precisely, it is a variety that can be expressed as the quotient of a given projective space by a group action of a linear algebraic group.
A narrow bipolar pulse is a type of electrical signal characterized by its short duration and bipolar nature, meaning that it alternates between positive and negative voltages. These pulses are typically used in various applications, such as in communication systems, digital signal processing, or biomedical devices like nerve stimulators. ### Key Characteristics: 1. **Narrow Pulse Width**: The "narrow" aspect refers to the short duration of the pulse, which can be measured in microseconds or nanoseconds.
Mixed boundary conditions refer to a type of boundary condition used in the context of partial differential equations (PDEs), where different types of conditions are applied to different parts of the boundary of the domain. Specifically, a mixed boundary condition can involve both Dirichlet and Neumann conditions, or other types of conditions, imposed on different sections of the boundary.