Question

What is the relationship between string theory and quantum field theory ?
This question is only for Physicist .

Answer 1

Many principles in quantum field theory are explained or get further insight ,in string theory :

Emission and absorption: one of the most basic building blocks of quantum field theory , is notion that particles such as electron can emit and absorb other particles such as photon .Thus , an electron may just split into an electron plus a photon with a certain probability This process is the integral part of the string theory.The mode on the original string also splits into two parts resulting in two string which possibly represent two different particles .

Coupling constant : in the quantum field theory roughly the probability for one particle to emit or absorb another particles

Spin : Each particles in quantum field theory has a particular spin which is an integral angular momentum.

Gauge symmetry : In quantum mechanics , the mathematical description of physical fields including non - physical states . In order to omit these states from description of every physical states ,a mechanism called gauge symmetry .This is true in string theory .

Fermions : In bosonic string, a string can be a described as an elastic one dimensional object ' living' in space time .

Renormalization is another thing in string theory .