PSC 2020.09.11 Nima Arkani-Hamed, Institute for Advanced Study 

Nima is one of the smartest people out there.

I want more Nima!

"It is very likely that the notion of spacetime is approximate." Can Lestone's theory of virtual cross sections be successfully developed in terms of string theory? Consider the following speculation: Tachyonic Network Hypothesis (with subsidiary hypotheses A,B,C,D): (A) String theory with the infinite nature hypothesis implies the Big Bang, the inflaton field, and, after quantum averaging, Einstein’s field equations are totally correct. For times shorter than one Planck-time unit, the concepts of measurement, energy, and spacetime fail. For times in the range from one Planck-time unit to one hundred thousand Planck-time units, the Heisenberg uncertainty principle needs to be replaced by a generalized uncertainty principle (GUP). Call this the GUP range. For times greater than one hundred thousand Planck time units, the Heisenberg uncertainty principle is valid for almost all purposes. (B) In the GUP range, 3-dimensional space needs to be replaced by 9-dimensional virtual space, which consists of 3 copies of the unit sphere in quaternionic space. In the GUP range, 1-dimensional time needs to be replaced by 2-dimensional time, which consists of 1 dimension of measurable time and 1 dimension of non-measurable, imaginary time. Non-measurable, imaginary time is bounded. As non-measurable, imaginary time shrinks to zero, 9-dimensional virtual space shrinks to 3-dimensional measurable space. Massless bosons have 0-dimensional virtual cross sections. Massive bosons have 1-dimensional virtual cross sections. Leptons have 2-dimensional virtual cross sections. Quarks have 8-dimensional virtual cross sections. (C) To 36 quarks, 12 leptons, 9 massless bosons, and 4 massive bosons, adjoin the graviton, the axion, and the inflaton to get 64 fundamental particles. There is a 256-dimensional lattice approximation for string theory in which there are 64 virtual particle paths with each particle path having 4 dimensions of uncertainty. The 256-dimensional lattice approximation with 8 dimensions of virtual-cross-sectional uncertainty generates 264 dimensions of stringy uncertainty, which can be decomposed into 11 copies of the Leech lattice. (D) Each virtual particle has 11 copies of the Leech lattice associated with it. As virtual particles collapse into measurable particles, there is an enormous network of non-measurable virtual tachyons, which link the measurable particles together. The virtual tachyons do not last long enough to be directly measured, but they do allow a transient violation of energy conservation which is postulated in Lestone’s theory of virtual cross sections. The massless virtual particles collapse into 10 possible massless bosons. The massive virtual particles (which have imaginary mass-energy) collapse into 54 possible bosons. There might be other measurable particles for which this lattice approximation scheme fails (e.g. SUSY, magnetic monopoles, Majorana fermions), but the lattice approximation based upon 11 copies of the Leech lattice does work well enough to justify Lestone’s theory of virtual cross sections.

Nima is worth the neurological issues, but there may be some simple exercises that would help overcome them.

Thanks Nima, very interesting! May I suggest you change the video title to increase findability! It's a little abstract as it is!

Is Prof Nima on high? He is going at 200mph without breaks..