## Tuesday, October 03, 2006

### The Standard Model singularity

Herman Verlinde and Martijn Wijnholt have been looking into the question what kind of singularity is the holographic dual to the Standard Model - more precisely, to the SSM where the missing initial "M" indicates an extended Higgs sector.

They have ended up with a dP_8 singularity (the most complicated del Pezzo surface). Their idea is that the Standard Model is everything there is - which is why it comes from a single D3-brane probing a particular singularity - and everything else is just quantum gravity encoded in the compact part of the Calabi-Yau manifold.

Today, in a
with David Morrison, Matthew Buican, and Dmitry Malyshev, they embed the singular picture into a compact Calabi-Yau manifold that they can explicitly construct: this manifold had to satisfy rather strong topological constraints that they explain. They also require that only the right hypercharge which is a particular U(1) combined from the U(1)'s in the original
• U(3) x U(2) x U(1)7
quiver gauge theory survives at low energies. No one can guarantee that their picture that kind of separates gravity from the rest will be correct. But it is a rather naturally motivated one that leads to a nearly unique result which is why it is very interesting.