## The New Odd Couple? Point Particles and Gravity

Have quantum particles and gravity been reconciled?

Whatever will we do with all that string we’ve been collecting?

😉

“… Matter is governed by the laws of quantum mechanics, but so far, Einstein’s theory has resisted all attempts to reconcile it with quantum mechanics. Our understanding of subatomic phenomena is encoded in the standard model of elementary particle physics (based on an extension of quantum electrodynamics called Yang-Mills theory) which, for all we know, correctly describes the interactions of known matter within relativistic quantum field theory. This is an elaborate mathematical framework, which took many decades to develop and still presents many difficulties. These are due in particular to the necessity of having to deal with infinite expressions appearing at intermediate stages of every calculation, and their removal by a procedure referred to as renormalization. Infinities generally arise because of the pointlike nature of elementary particles, implying short distance singularities in the formulas (or “ultraviolet infinities” in momentum space). To this day we are not sure whether quantum field theory makes sense as a mathematical theory, but we do know that it works exceedingly well in perturbation theory, yielding spectacular agreement between theory and experiment. However, applying the established rules of quantum field theory to Einstein gravity and its generalizations results in complete failure—with one possible exception: As Zvi Bern, John Carrasco, and Henrik Johanssen at UCLA, Lance Dixon at the Stanford Linear Accelerator Center, and Radu Roiban at Pennsylvania State University, all in the US, report in Physical Review Letters, N=8 supergravity, distinguished among all other field theories by its maximal supersymmetry, may evade this dilemma…”

Vanquishing Infinity: Ultraviolet Behavior of N=8 Supergravity at Four Loops – APS Viewpoint

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Math World | The New Odd Couple? Point Particles and Gravity « the observer effect said this on August 21, 2009 at 12:42 pm |

“Infinities generally arise because of the point-like nature of elementary particles.” Today I had a thought while driving to the store. Taking my thoughts further on 2D spheres, if such a thing existed and represented elementary particles, is it possible that we experience 3D in a 2D universe? The interlacing of 2D fabrics would give the illusion of a 3D universe in that 2D spheres would appear to express themselves as 3D elementary particles. 2D elementary particles would be point-like, one could never know there “size”, only their position. I also realized that locality (a point) is only valid within the size ranges that dimensions can be experienced or expressed. Infinity does not exist in nature, only within equations (and our ability to conceive them,) therefore; a valid theorem should break down approaching plus or minus infinities. Just a pedestrian thought, I never did well in math. http://wordpress.trethowan.org/?p=83

Mike Trethowan said this on August 30, 2009 at 4:45 pm |