Three utilities problem
The Three Utilities Problem is a classic problem in graph theory and combinatorial optimization. It involves connecting three houses to three utility services (like water, electricity, and gas) without any of the utility lines crossing each other. In more formal terms, the problem can be visualized as a bipartite graph where one set contains the three houses and the other set contains the three utilities.
Toroidal graph
A toroidal graph is a type of graph that can be embedded on the surface of a torus without any edges crossing. In other words, it can be drawn on the surface of a doughnut-shaped surface (a torus) in such a way that no two edges intersect except at their endpoints.
Turán's brick factory problem
Turán's brick factory problem is a classic problem in combinatorial optimization, particularly in the field of graph theory. It is named after the Hungarian mathematician Paul Erdős and his colleague László Turán, who studied problems involving extremal graph theory. The problem can be described as follows: Imagine a brick factory that produces bricks of various colors.
Wilson operation
The Wilson operation, also known as the Wilson loop, is a concept from quantum field theory, particularly in the context of gauge theories. It is named after Kenneth Wilson, who introduced it in the early 1970s as part of his work on lattice gauge theories and the study of confinement in quantum chromodynamics (QCD). In simple terms, the Wilson loop is a gauge-invariant quantity associated with the path of a loop in spacetime.
Amenable group
An **amenable group** is a type of mathematical structure studied in the field of group theory, specifically in the study of topological groups and functional analysis. The concept of amenability is related to the ability of a group to have a certain type of "invariance" property under averaging processes. A group \( G \) is called **amenable** if it has a left-invariant mean.
Chabauty topology
Chabauty topology is a concept used in algebraic geometry and arithmetic geometry, specifically in the study of the spaces of subvarieties of algebraic varieties. It is named after the mathematician Claude Chabauty, who developed this topology in the context of algebraic varieties and their rational points. In the Chabauty topology, one can think about the space of closed subsets of a given topological space (often within a certain context such as algebraic varieties).
Continuous group action
A **continuous group action** is a mathematical concept that arises in the field of topology and group theory. Specifically, it involves a group acting on a topological space in a way that is compatible with the topological structure of that space. ### Definition: Let \( G \) be a topological group and \( X \) be a topological space.
Covering group
In group theory, a branch of abstract algebra, a **covering group** is a concept that relates to the idea of covering spaces in topology, though it is used more specifically in the context of group representations and algebraic structures. A covering group can refer to a group that serves as a double cover of another group in the sense of group homomorphisms.
Topological ring
A **topological ring** is a mathematical structure that combines the concepts of a ring and a topology. Specifically, a topological ring is a ring \( R \) that is also equipped with a topology such that the ring operations (addition and multiplication) are continuous with respect to that topology.
The Grothendieck–Riemann–Roch theorem is a fundamental result in algebraic geometry and algebraic topology that extends classical Riemann–Roch theorems for curves to more general situations, particularly for algebraic varieties. The theorem originates from the work of Alexander Grothendieck in the 1950s and provides a powerful tool for calculating the dimensions of certain cohomology groups.
Bott periodicity theorem
Bott periodicity theorem is a central result in stable homotopy theory, named after the mathematician Raoul Bott. The theorem essentially states that the homotopy groups of certain topological spaces exhibit periodic behavior. More specifically, Bott periodicity is concerned with the stable homotopy groups of spheres and the stable homotopy classification of certain types of vector bundles.
National Wind Institute
The National Wind Institute (NWI) is a research and education organization based at Texas Tech University in Lubbock, Texas. It focuses on the study of wind-related phenomena, including wind energy, wind engineering, and the effects of wind on structures. The NWI aims to improve safety and resilience against severe wind events, such as tornadoes and hurricanes, as well as to promote the development of wind energy technologies.
Power flash
The term "Power Flash" can refer to different things depending on the context: 1. **Technology and Electronics**: In some technical contexts, "Power Flash" might refer to a rapid surge of electrical power, perhaps used in relation to systems that require brief high-power bursts, such as in certain motors or power supplies.
Satellite tornado
A satellite tornado is a term used to describe a smaller tornado that forms in close proximity to a larger, stronger parent tornado. These satellite tornadoes usually occur in the vicinity of the main vortex and are often seen rotating around it. They can develop from the same thunderstorm or supercell that produces the primary tornado, and while they are typically weaker than the main tornado, they can still cause damage.
Skipping tornado
A "skipping tornado" is not a widely recognized term in meteorology, but it may refer to a tornado that appears to have a non-continuous or intermittent path as it touches down and then lifts back into the cloud, only to potentially touch down again later. This phenomenon can sometimes give the visual impression of the tornado "skipping" along the ground rather than maintaining a constant, continuous path.
Storm Track
"Storm Track" can refer to several different contexts, but it generally relates to the monitoring and forecasting of weather patterns, particularly severe weather events like hurricanes, tornadoes, or winter storms. Here are a few possible interpretations: 1. **Meteorology**: In meteorological terms, a storm track indicates the path that a storm system is expected to follow as it moves through a particular area.
Tornado debris signature
A Tornado Debris Signature (TDS) is a specific pattern observed in radar data that indicates the presence of a tornado and the associated debris being lifted into the atmosphere. When a tornado occurs, it can pick up various materials from the ground, such as dirt, leaves, and man-made objects, and fling them into the air. This debris can create a distinct radar signature. Meteorologists use Doppler radar to detect these signatures during storm events.
Kazhdan's property (T)
Kazhdan's property (T) is a property of groups that was introduced by the mathematician David Kazhdan in the context of representation theory and geometric group theory. It is a strong form of compactness that relates to the representation theory of groups, particularly in how they act on Hilbert spaces.
Kronecker's theorem
Kronecker's theorem, also known as the Kronecker limit formula, is a result in number theory specifically related to the distribution of prime numbers and the behavior of certain algebraic objects. It can be particularly focused on the context of the theory of partitions or modular forms, but the term might refer to different results depending on the field.
Locally compact group
A **locally compact group** is a type of topological group that has the property of local compactness in addition to the group structure. Let's break down the definitions: 1. **Topological Group**: A group \( G \) is equipped with a topology such that both the group operation (multiplication) and the inverse operation are continuous.