- Membrane (M-Theory)
In
theoretical physics , a membrane, brane, or "p"-brane is a spatially extended mathematical concept that appears instring theory and its relatives (M-theory andbrane cosmology ). The variable "p" refers to the number of spatialdimensions of the brane. That is, a 0-brane is a zero-dimensional pointlike particle, a 1-brane is a string, a 2-brane is a "membrane", etc. Every "p"-brane sweeps out a ("p"+1)-dimensional "world volume" as it propagates throughspacetime .Description
Originally string theory was a theory of 1-branes called strings. By the mid-1990s it became apparent that the theory could be extended to also include higher dimensional objects. Typically these objects are "non-perturbative" features of the theory (meaning they do not appear in perturbation theory).
Besides the fundamental string (or F-string) of string theory and its
magnetic dual , theNS5-brane , the most important type of branes that appear are theD-brane s. Different types of D-branes appear in different theories. Even D"n"-branes for "n" appear intype IIA string theory where as the odd D"p"-branes appear intype IIB string theory .With the development of
M-theory , an extra dimension appeared and the fundamental string of string theory became a 2-dimensional membrane called anM2-brane (orsupermembrane ). Its magnetical dual is anM5-brane . The various branes of string theory are thought to be related to these higher dimensional M5-branes wrapped on various cycles.The M-theory states that strings of energy could grow into larger membranes or branes up to even the size of the universe.It also goes on to state that these strings need to vibrate in more than three dimensions (6) plus another dimension - time.
ee also
*
Black brane
*Brane cosmology
*Cyclic Universe Theory
*D-brane
*S-brane
*Multiverse
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