Quantum Gravity Tapio Salminen

Chapter 1. Motivation

Theoretical physics

You should do things that make you happy!

Or could it possibly be?

Have to dig a little deeper...

“ Curiosity is a powerful human impulse – some distance below sex and greed, I grant you, but far ahead of altruism – and I was simply curious.” -- Robert Harris, Ghost

Chapter 2. Quantum gravity

Quantum Gravity Loops Horava gravity Quantum graphity NC QFT Strings

The heart of the problem - Einstein's equations

Geometry = Energy

Ideas of emergent gravity

String theory Ideas of emergent gravity A coherent state of gravitons A coherent state of gravitons

String theory A coherent state of gravitons Still background dependent! Ideas of emergent gravity A coherent state of gravitons

Loop quantum gravity Background independent Problem of time Ideas of emergent gravity

Background independent

Problem of time

The problem of time

The problem of time Quantum mechanics

The problem of time General relativity

“ Motion and change are primary. Nothing is, except in a very approximate and temporary sense. ... if we want to think fundamentally we must not lose sight of the essential fact that 'is' is an illusion.” -- Lee Smolin

Quantum Gravity Loops Horava gravity Quantum graphity NC QFT Strings

Chapter 3. Quantum spacetime

Quantum theory

Quantum mechanics Quantum oscillator Quantum phase space

Quantum field theory Quantum fields and their excitations

Quantum coordinates Quantum spacetime

Looks like it will be very complicated...

Start with a usual, commutative , quantum field theory: Noncommutative quantum field theory

Noncommutative quantum field theory ...and insert modified products :

You will still have to check everything starting from scratch!

particles symmetries Interactions causality spin-statistics CPT Start checking!

So this is all just familiar calculations with a bit more math ?