# What is the brane theory

## Bran

A bran brane), more precisely one p-bran, is, according to string theories, a vibratory object with the dimension p. The name works Paul Townsend back and is based on the word membrane (engl. membrane) ajar.

### Branes have different dimensions

Branes are generalizations of strings that were first found historically. This also gave rise to the name etymologically String theories. The dimension p defines various objects. Is p = 0, it is a Point particle (0 bran), p = 1 corresponds to a one-dimensional thread, the actual one String (or 1-bran), p = 2 is a two-dimensional surface (2-bran) that one membrane is called. There are also higher-dimensional branes, 3-branes, etc.

### Branes as particles or as black holes

The branes represent the particles of the Standard Model known to us and also many that have not yet been discovered, especially if branes are considered in supersymmetry (SUSY). From a general point of view, the p-branes should be finite Democritus postulated 'atoms' (atomos, Greek: 'indivisible'), the indivisible, fundamental constituents of matter. Branes can also describe entire stellar objects, such as classic black holes. Branes serve as a generalization of the point-like black hole: this is just identified with a 0 brane. The first generalization as a 1-brane is called Black string (engl. black string), the second is called the 2-brane Black brane (engl. black brane). Depending on the assumed action functional or Lagrangian (Einstein-Hilbert-Lagrangian, Einstein-Maxwell-Lagrangian, etc.), brane generalizations of the classic Schwarzschild solution (uncharged, static), Reissner-NordstrÃ¸m solution (charged, static) or Kerr - Find Newman solution (loaded, rotating).

### Strings also hold the edge

With open strings you can boundary conditions at its ends and fix them in a certain way. Analogous to D.irichlet-Boundary condition in classical electrodynamics is what the string theorists called them D-branes.
Both Dp branes the ends of the string are located on one or possibly different p-dimensional D-branes.
Finally denotes the M-brane the branes of M-theory, which are made up of strings (1-branes) and p-branes.

### A whole cosmos on the Bran

The theoretical concept with branes is called comprehensive as Branenworld (engl. brane world) or also Brane World Scenario. This formalism has permeated all string theories. In theBranen cosmology the branes are applied in the context of relativistic cosmology and clearly expand the concepts of (four-dimensional) standard cosmology. As required by string theories, the existence of extra dimensions is assumed. The branes are typically three-dimensional (3-branes) and form Hypersurfaces in the higher dimensionalBulk (English, spoken 'balk'). The branes can be based on this bulk geometrystatically fixed be, as in the Randall-Sundrum models or through the mediation of a scalar field oscillate against each other. These Branch dynamics comes about through the interaction with the bulk scalar field. In the Ecpyrotic Scenario and the Cyclic Universe, this field is called Radion. The dynamics go so far that the branes can collide, which is cosmologically interpreted as the Big Bang. This is the first time that Ekpyrosis and Cyclical Model deliver one Cause of the big bang. The reason was nothing less than a world collision!