Search results
Results From The WOW.Com Content Network
Bosonic string theory is the original version of string theory, developed in the late 1960s.It is so called because it contains only bosons in the spectrum.. In the 1980s, supersymmetry was discovered in the context of string theory, and a new version of string theory called superstring theory (supersymmetric string theory) became the real focus.
String theory is a theoretical framework that attempts to address these questions. The starting point for string theory is the idea that the point-like particles of particle physics can also be modeled as one-dimensional objects called strings. String theory describes how strings propagate through space and interact with each other.
Schwarz and Scherk argued that string theory had failed to catch on because physicists had underestimated its scope. This led to the development of bosonic string theory. String theory is formulated in terms of the Polyakov action, [37] which describes how strings move through space and time. Like springs, the strings tend to contract to ...
In string theory, a worldsheet is a two-dimensional manifold which describes the embedding of a string in spacetime. [1] The term was coined by Leonard Susskind [2] as a direct generalization of the world line concept for a point particle in special and general relativity.
Because string theory implies that the Universe has more dimensions than we expect—26 for bosonic string theories and 10 for superstring theories—we have to find a reason why the extra dimensions are not apparent. One possibility would be that the visible Universe is in fact a very large D-brane extending over three spatial dimensions.
The Nambu–Goto action is the simplest invariant action in bosonic string theory, and is also used in other theories that investigate string-like objects (for example, cosmic strings). It is the starting point of the analysis of zero-thickness (infinitely thin) string behaviour, using the principles of Lagrangian mechanics .
This approach can be dated back to a paper by Gabriele Veneziano [1] that shows how an inflationary cosmological model can be obtained from string theory, thus opening the door to a description of pre-Big Bang scenarios. The idea is related to a property of the bosonic string in a curve background, better known as nonlinear sigma model.
This discovery can be considered the birth of string theory, [2] as the invention of string theory came about as a search for a physical model which would give rise to such a scattering amplitude. In particular, the amplitude appears as the four tachyon scattering amplitude in oriented open bosonic string theory .