Geneva: Providing a Solution to the Worst-Ever Prediction in Physics

[bystander]

Providing a Solution to the Worst-Ever Prediction in Physics
University of Geneva, Switzerland | 2019 Aug 29

A UNIGE physicist has proposed a new approach to solving one of the biggest theoretical problems in physics: the cosmological constant.

The cosmological constant, introduced a century ago by Albert Einstein in his theory of general relativity, is a thorn in the side of physicists. The difference between the theoretical prediction of this parameter and its measurement based on astronomical observations is of the order of 10¹²¹. It’s no surprise to learn that this estimate is considered the worst in the entire history of physics. In an article to be published in Physics Letters B, a researcher from the University of Geneva (UNIGE), Switzerland, proposes an approach that may seemingly resolve this inconsistency. The original idea in the paper is to accept that another constant – Newton’s universal gravitation G, which also forms part of the equations on general relativity – may vary. This potentially major breakthrough, which has been positively received by the scientific community, still needs to be pursued in order to generate predictions that can be confirmed (or refuted) experimentally. ...

The most precise observations of supernovae, and especially of the cosmic microwave background (microwave radiation that comes from all parts of the sky and which is considered to be left over from the Big Bang), have made it possible to measure an experimental value for this cosmological constant. The result is a very small figure (1.11 x 10^-52 m^-2) that is nevertheless large enough to generate the desired effect of accelerated expansion.

The problem is that the theoretical value of the cosmological constant is very different. This value is obtained using quantum field theory: this holds that pairs of particles on a very small scale are created and destroyed almost instantaneously at every point of space and at any moment. The energy of this “vacuum fluctuation” -- a very real phenomenon -- is interpreted as a contribution to the cosmological constant. But when its value is calculated, an enormous figure is obtained (3.83 x 10⁺⁶⁹ m^-2), which is largely incompatible with the experimental value. This estimate represents the largest gap ever obtained (by a factor of 10¹²¹, i.e., 1 followed by 121 zeros) between theory and experiment across science. ...

On the Cosmological Constant Problem ~ Lucas Lombriser

• Physics Letters B 797:134804 (10 Oct 2019) DOI: 10.1016/j.physletb.2019.134804
• arXiv.org > gr-qc > arXiv:1901.08588 > 23 Jan 2019