Abstract: The aim of present talk is to introduce topological solitons in field theory and string theory. First classical solitons history and the way they entered physics is reviewed.
To start the subject of topological solitons, first the conditions that
these solitons appear are discussed and then solitons of different
dimension are introduced. Discussion includes solitons in one spatial
dimension (kinks), two spatial dimensions (vortices) and three
spatial dimensions (monopoles).
Solitons of four dimensional Euclidean space are called instantons.
Reasons for making the space Euclidean will be given and then
instantons in QCD will be discussed. As an application of instanton
effects, its contribution to the parton distribution function, in a
qualitative manner will be presented.
Because one of the important applications of supersymmetry is in
soliton formalism, after some introduction to the subject, BPS solitons
will be introduced.
Finally solitons in string theory will be discussed. With the
introduction of black holes as gravitational solitons, the role of black
branes in supergravity is mentioned. After introducing the concept of
dualities and the point that supergravities are low energy limit of
string theories, D-branes are introduced as solitons of string theory.
Some of the implications of the concept of D-branes will be discussed.
As one of the important implications of solitons in strin theory, one of
the most stringent method of testing Ads/CFT will be discussed in
Time: Wednesday, October 30, 2013 at 15:00 in Larak Seminar Room