In
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...
, an M5-brane is a fundamental
brane
In string theory and related theories (such as supergravity), a brane is a physical object that generalizes the notion of a zero-dimensional point particle, a one-dimensional string, or a two-dimensional membrane to higher-dimensional objec ...
of
M-theory
In physics, M-theory is a theory that unifies all Consistency, consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1 ...
. As such, it can be described explicitly as a black brane solution to
eleven-dimensional supergravity, the low-energy limit of M-theory. In particular, it carries a
magnetic charge under the 3-form gauge field of the 11-dimensional
supergravity multiplet. The M5-brane is the
electric-magnetic dual of the
M2-brane.
Upon
compactification, the M5-brane becomes either the
D4-brane or the
NS5-brane of
type IIA supergravity, depending on whether the 11-dimensional theory is reduced along a direction parallel or orthogonal to the M5-brane, respectively.
The worldvolume theory on a stack of M5-branes at low energies is the
six-dimensional N=(2,0) superconformal field theory (SCFT) with
gauge algebra of the
A-type. Other gauge algebras can be realised by placing the stack of branes on a singularity.
The PST model provides a Green-Schwarz description of the worldvolume physics of a single M5-brane.
On the other hand, direct knowledge of the non-Abelian case, for instance via a
Lagrangian description, is not presently available, due to various technical difficulties. Since superconformal symmetry is only available in 6 or lower spacetime dimensions, this maximally
supersymmetric theory may be used to derive an infinite number of other theories. Furthermore, via the
AdS/CFT correspondence
In theoretical physics, the anti-de Sitter/conformal field theory correspondence (frequently abbreviated as AdS/CFT) is a conjectured relationship between two kinds of physical theories. On one side are anti-de Sitter spaces (AdS) that are used ...
, the M5-brane worldvolume theory can be used to study
M-theory
In physics, M-theory is a theory that unifies all Consistency, consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1 ...
on asymptotically
Anti-de Sitter (AdS) spacetimes.
Despite the lack of a Lagrangian formulation, brane constructions provide evidence that the M5-brane worldvolume theory can support four- and two-codimensional solitonic excitations, namely self-dual strings and three-branes.
References
String theory
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