文档介绍：String Theory: A Status Report
N. Seiberg
Institute for Advanced Study
2004
Foundations of Modern Physics
Quantum Theory
Special Relativity
General Relativity
Quantum Mechanics + Special Relativity
=
Quantum Field Theory
The standard model of particle physics
Unprecedented ess!
Adding Gravity/General Relativity
Many problems arise:
moon
earth
graviton
graviton
electron
Quantum fluctuations are infinite!
Gravity = General Relativity
= Modification of space-time
This is not merely a technical problem
but a conceptual problem.
We should not expect the quantization to be easy.
Conceptual problems:
The light-cone undergoes quantum fluctuations
How to maintain causality?
Information loss in black holes(?)
Is the theory unitary?
The cosmological constant 10-120M4Planck
Why so small? Calculate it.
Cosmology, early Universe, inflation
Wave function of the Universe
Initial conditions
Challenge:
Combine General Relativity with
Quantum Mechanics
String Theory
Invented in the late 60’s as a theory of the strong interactions.
Mid 70’s: String theory is a theory of gravity!
Gravity is not an option in string theory.
It is a logical consequence of it!
Main idea: the fundamental building blocks
are not point-like particles but strings
Their small size (10-33cm) makes them look point-like.
Different vibration modes of the string
are different particles.
electron quark
Very economical!