Some BIG IDEAS from summer conferencesSome BIG IDEAS from summer conferences

1) The emergence of space2) A model for quarks, leptons, gauge bosons3) All particles in one representation –E8

4) Photons emerging from non-gauge interactions

SupersymmetryGrand UnificationBaryogenesis TechnicolorKaluza KleinString TheoryInflationMultiverseBranesLarge Extra Dimensions

Conferences are often the place to spread new ideas

There have not been many big ideas lately at regular conferences

The emergence of space

“Quantum graphity”

Fotini Markopoulou - Perimeter

Basic idea: - think of spacetime as a lattice of points -endowed with a Hamiltonian - maximally connected space - at low energy, Minkowski space emerges

New idea for cosmology, locality etc

Phenomenology of locality:

Locality, causality are properties of all regular QFTs - but could be violated in some theories

Gravity: -distances subject to quantum fluctuations - violation should be 1/MP+ suppressed

Branes:

Fotini’s space: - major violations possible - black hole example

A model for all the particles and interactions

Sundance Bilson-Thompson - Perimeter

Basic idea: - like composite models – what makes up quarks etc - novel outlook – maybe also explains interactions

Problems: - no right handed neutrino - need Majorana mass, Higgs triplet - no Higgs so far - gravity missing (but may be part of LQG)

Potential promise: - rationale for the world that we see - reframes the problems

But a lot left to do - math of braided networks

All the particles in one representation Garrett Lisi - FQXi

Basic idea: - in genre of finding a unified theory - everything (including gravity) fits in one rep of E8

Wen will give seminar here Friday Oct 26

Hopes and goals: - perhaps describe all interactions as “emergent” - logical way to build a finite theory - Wen also has paper on emergent gravity

Problems: - no chiral fermions yet - Weinberg Witten theorem for gravity?? - no Higgs

Some BIG IDEAS from summer conferencesSome BIG IDEAS from summer conferences

1) The emergence of space2) A model for quarks, leptons, gauge bosons3) All particles in one representation –E8

4) Photons emerging from non-gauge interactions