The amazing world of String Theory

254 Pages·2012·7.37 MB·English

by  Keshav Dasgupta

The amazing world of String Theory
Keshav Dasgupta
Department of Physics
McGill University
Montréal, QC, CANADA
Dasgupta (McGill) StringTheory Homer2012 1/92
The starting point is the so-called Nambu-Goto action
Z r ∂Xµ∂Xν
S = −T d2σ −det η
NG ∂σα ∂σβ µν
where T is the tension of the string, σα are the world-sheet
coordinates, Xµ are the space-time coordinates and η is the flat
µν
spacetime metric.
String theory is an amazing
branch of science that manages to
unify all matter and interactions
under one simple idea
Dasgupta (McGill) StringTheory Homer2012 2/92
where T is the tension of the string, σα are the world-sheet
coordinates, Xµ are the space-time coordinates and η is the flat
µν
spacetime metric.
String theory is an amazing
branch of science that manages to
unify all matter and interactions
under one simple idea
The starting point is the so-called Nambu-Goto action
Z r ∂Xµ∂Xν
S = −T d2σ −det η
NG ∂σα ∂σβ µν
Dasgupta (McGill) StringTheory Homer2012 2/92
String theory is an amazing
branch of science that manages to
unify all matter and interactions
under one simple idea
The starting point is the so-called Nambu-Goto action
Z r ∂Xµ∂Xν
S = −T d2σ −det η
NG ∂σα ∂σβ µν
where T is the tension of the string, σα are the world-sheet
coordinates, Xµ are the space-time coordinates and η is the flat
µν
spacetime metric.
Dasgupta (McGill) StringTheory Homer2012 2/92
You really didn’t come here to
listen to this, did you? I was just
kidding!
Lets start our talk now hopefully
I’ll manage to explain what on
earth is string theory! Its also a
good time to open your can of
draft beer!
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
Dasgupta (McGill) StringTheory Homer2012 3/92
I was just
kidding!
Lets start our talk now hopefully
I’ll manage to explain what on
earth is string theory! Its also a
good time to open your can of
draft beer!
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
You really didn’t come here to
listen to this, did you?
Dasgupta (McGill) StringTheory Homer2012 3/92
Lets start our talk now hopefully
I’ll manage to explain what on
earth is string theory! Its also a
good time to open your can of
draft beer!
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
You really didn’t come here to
listen to this, did you? I was just
kidding!
Dasgupta (McGill) StringTheory Homer2012 3/92
hopefully
I’ll manage to explain what on
earth is string theory! Its also a
good time to open your can of
draft beer!
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
You really didn’t come here to
listen to this, did you? I was just
kidding!
Lets start our talk now
Dasgupta (McGill) StringTheory Homer2012 3/92
Its also a
good time to open your can of
draft beer!
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
You really didn’t come here to
listen to this, did you? I was just
kidding!
Lets start our talk now hopefully
I’ll manage to explain what on
earth is string theory!
Dasgupta (McGill) StringTheory Homer2012 3/92
The more useful version is the so-called Polyakov action, that
goes in the following way
Z √
S = −T d2σ hhαβ∂ Xµ∂ Xνη
α β µν
You really didn’t come here to
listen to this, did you? I was just
kidding!
Lets start our talk now hopefully
I’ll manage to explain what on
earth is string theory! Its also a
good time to open your can of
draft beer!
Dasgupta (McGill) StringTheory Homer2012 3/92