String background
Encyclopedia
In theoretical physics
, a string background refers to the set of classical values of quantum fields in spacetime
that correspond to classical solutions of string theory
. Such a background is associated with geometry that solves Einstein's equations (with higher order corrections) or their generalizations and with the values of other fields. These fields may encode the information about the shape of the hidden dimensions; the size of various electromagnetic fields and their generalizations; the values of fluxes; and the presence of additional objects such as D-brane
s and orientifold
planes. The full physics of string theory can always be thought of as a system of infinitely many quantum fields expanded around a given string background.
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
, a string background refers to the set of classical values of quantum fields in spacetime
Spacetime
In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...
that correspond to classical solutions of string theory
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...
. Such a background is associated with geometry that solves Einstein's equations (with higher order corrections) or their generalizations and with the values of other fields. These fields may encode the information about the shape of the hidden dimensions; the size of various electromagnetic fields and their generalizations; the values of fluxes; and the presence of additional objects such as D-brane
D-brane
In string theory, D-branes are a class of extended objects upon which open strings can end with Dirichlet boundary conditions, after which they are named. D-branes were discovered by Dai, Leigh and Polchinski, and independently by Hořava in 1989...
s and orientifold
Orientifold
In theoretical physics orientifold is a generalization of the notion of orbifold, proposed by Augusto Sagnotti in 1987. The novelty is that in the case of string theory the non-trivial element of the orbifold group includes the reversal of the orientation of the string...
planes. The full physics of string theory can always be thought of as a system of infinitely many quantum fields expanded around a given string background.