About the book
The corresponding subject will be the best candidate for the description of Quantum Gravity as a fourth force in the Universe. Also by this subject one can explain the Quantum Cromo-dynamic and hadron processes. On the other hand, it can be a candidate for Cosmological explanations of the Universe. From a mathematical point of view, this subject is related to topology, algebra and group theory. The most important thing about it is that is used for holography. The aim of publishing this book is to create a reference book on the topic of string theory. The chapter titles are selected in the way to cover the wide topic of string theory but not limited. We invite all experts in the fields of Particle physics, Cosmology and other fields of physics to submit themselves proposals in the selected topics and other related topics of string theory to load the book.