Mabuchi functional
The Mabuchi functional is an important concept in differential geometry, particularly in the study of Kähler manifolds and the geometric analysis of the space of Kähler metrics. It was introduced by the mathematician Toshiki Mabuchi in the context of Kähler geometry. The Mabuchi functional is a functional defined on the space of Kähler metrics in a fixed Kähler class and is closely related to the notion of Kähler-Einstein metrics.
Margulis lemma
The Margulis Lemma is a result in the theory of manifolds and geometric group theory, named after the mathematician Gregory Margulis. It provides important insights into the structure of certain types of groups acting on hyperbolic spaces. The lemma primarily concerns the actions of groups on hyperbolic spaces and focuses on the properties of relatively compact subsets and their orbits under isometries.
Maurer–Cartan form
The Maurer–Cartan form is a fundamental concept in the theory of Lie groups and differential geometry, particularly in the study of Lie group representations and the geometry of principal bundles. Given a Lie group \( G \), the Maurer–Cartan form is a differential 1-form on the Lie group that captures information about the group structure in terms of its tangent space.
Maximal surface
A maximal surface is a type of surface in differential geometry characterized by a certain property related to its mean curvature. Specifically, a maximal surface is defined as a surface that locally maximizes area for a given boundary, or equivalently, a surface where the mean curvature is equal to zero everywhere.
Mean curvature
Mean curvature is a geometric concept that arises in differential geometry, particularly in the study of surfaces. It measures the average curvature of a surface at a given point and is an important characteristic in the study of minimal surfaces and the geometry of manifolds. For a surface defined in three-dimensional space, the mean curvature \( H \) at a point is given by the average of the principal curvatures \( k_1 \) and \( k_2 \) at that point.
Mean curvature flow
Mean curvature flow is a mathematical concept used in differential geometry and geometric analysis. It describes the evolution of a surface in space as it flows in the direction of its mean curvature. The mean curvature of a surface at a point is intuitively understood as a measure of how the surface curves at that point; it is essentially the average of the curvatures in all directions.
Metric signature
In the context of general relativity and differential geometry, a **metric signature** refers to the convention used to describe the character of the components of the metric tensor, which encodes the geometric and causal structure of spacetime. The metric tensor \( g_{\mu\nu} \) is a fundamental object in general relativity that allows for the computation of distances and angles in a given manifold (the mathematical representation of spacetime).
Metric tensor
The metric tensor is a fundamental concept in differential geometry and plays a key role in the theory of general relativity. It is a mathematical object that describes the geometry of a manifold, allowing one to measure distances and angles on that manifold. ### Definition In a more formal sense, the metric tensor is a type of tensor that defines an inner product on the tangent space at each point of the manifold. This inner product allows one to compute lengths of curves and angles between vectors. ### Properties 1.
Milnor–Wood inequality
The Milnor–Wood inequality is a result in differential geometry and topology that relates to the study of compact manifolds and especially to the theory of bundles over these manifolds. It provides a constraint on the ranks of vector bundles over a manifold in terms of the geometry of the manifold itself. Specifically, the Milnor–Wood inequality offers a bound on the rank of a vector bundle over a compact surface in relation to the Euler characteristic of the surface.
The Minakshisundaram-Pleijel zeta function is a mathematical concept that arises in the study of the spectral theory of differential operators, particularly in the context of boundary value problems and the behavior of eigenvalues of differential equations. Specifically, for a differential operator defined on a certain domain (like a bounded interval or a bounded region in higher dimensions), the Minakshisundaram-Pleijel zeta function serves as a tool to encode the distribution of eigenvalues.
Minimal surface
A minimal surface is a surface that locally minimizes its area for a given boundary. More formally, a minimal surface is defined as a surface with a mean curvature of zero at every point. This means that, at each point on the surface, the surface is as flat as possible and does not bend upwards or downwards. Minimal surfaces can often be described using parametric equations or as graphs of functions.
Minkowski problem
The Minkowski problem is a classic problem in convex geometry and involves the characterization of convex bodies with given surface area measures. More formally, the problem is concerned with the characterization of a convex set (specifically, a convex body) in \( \mathbb{R}^n \) based on a prescribed function that represents the surface area measure of the convex body.
Monodromy
Monodromy is a concept from algebraic geometry and differential geometry that describes how a mathematical object, such as a fiber bundle or a covering space, behaves when you move around a loop in a parameter space.
Monopole moduli space
Monopole moduli space is a concept in theoretical physics and mathematics, particularly in the areas of gauge theory, differential geometry, and algebraic geometry. It refers to the space of solutions to certain equations associated with magnetic monopoles, which are hypothetical particles proposed in various field theories, especially in the context of non-Abelian gauge theories. ### Context and Background 1.
Mostow rigidity theorem
Mostow rigidity theorem is a fundamental result in the field of differential geometry, particularly in the study of hyperbolic geometry. It states that if two closed manifolds (or more generally, two complete Riemannian manifolds that are simply connected and have constant negative curvature) are isometric to each other, then they are also equivalent up to a unique way of deforming them.
Motion (geometry)
In geometry, "motion" refers to the transformation of a geometric figure in space. This can involve changing the position, orientation, or size of the figure while maintaining its intrinsic properties. The main types of geometric motions include: 1. **Translation**: This involves sliding a shape from one position to another without rotating it or changing its size. Every point in the shape moves the same distance in the same direction.
Moving frame
A "moving frame" can refer to different concepts depending on the context, including mathematics, physics, and engineering. Here are a few interpretations: 1. **Mathematics (Differential Geometry)**: In the context of differential geometry, a moving frame is often used to describe a set of vectors that vary along a curve or surface.
Musical isomorphism
Musical isomorphism is a concept in music theory and musicology that refers to a structural similarity or correspondence between different musical works or musical elements. In essence, it means that two pieces of music can be considered equivalent in terms of their underlying structure, even if the surface details—such as melody, rhythm, or instrumentation—are different.
Myers's theorem
Myers's theorem is a result in Riemannian geometry, which concerns the relationship between the geometry of a complete Riemannian manifold and its topology. Specifically, the theorem states that if \( M \) is a complete Riemannian manifold that has non-negative Ricci curvature, then \( M \) can be isometrically embedded into a Euclidean space of a certain dimension.
Myers–Steenrod theorem
The Myers–Steenrod theorem is an important result in differential geometry, particularly in the study of Riemannian manifolds. It primarily deals with the structure of Riemannian manifolds that have certain properties related to curvature.