December 20, 2018
A brand new cosmology mannequin means that our Universe has a mirror picture within the type of an “antiuniverse” that existed earlier than the large bang.
L. Boyle/Perimeter Institute for Theoretical Physics
From a sure vantage level, our Universe appears to be like lopsided. Time runs ahead as house expands, and there’s extra matter than antimatter. This appears to violate a basic symmetry, referred to as CPT symmetry, that claims physics is unchanged when time, house, and matter-antimatter are all flipped. To steadiness out the cosmos, Latham Boyle, Kieran Finn, and Neil Turok from the Perimeter Institute for Theoretical Physics in Canada suggest that the large bang was additionally the place to begin of an antiuniverse, the place time runs in the other way and antimatter dominates. They present that such a CPT-symmetric mannequin will not be solely per the recognized cosmic growth historical past but additionally supplies a simple rationalization for darkish matter.
The CPT-symmetric mannequin is an alternative choice to inflation, which assumes that the Universe went via a quick epoch of exponential progress proper after the large bang. This fast growth can clarify sure cosmological observations, nevertheless it requires the existence of extra, nonetheless hypothetical quantum fields. Boyle and colleagues present that their proposal can clarify early cosmic evolution with out inventing new physics. Within the CPT-symmetric mannequin, time and house circulation repeatedly throughout the large bang, and the antiuniverse that emerges within the detrimental time course behaves like a mirror reflection of our Universe.
The crew has but to indicate whether or not this mannequin can reproduce sure observations that the inflation situation explains—such because the uniformity of the cosmos on giant scales. Nonetheless, the brand new mannequin provides a pure rationalization for darkish matter: a CPT-symmetric Universe would produce giant numbers of very huge sterile neutrinos. Such superheavy neutrinos may also be the supply of lately noticed high-energy cosmic-ray showers (see 18 October 2018 Synopsis).
This analysis is revealed in Bodily Evaluation Letters.
Michael Schirber is a Corresponding Editor for Physics primarily based in Lyon, France.
Making Swallowing Safer
Experiments utilizing a duplicate mannequin of the mouth and throat may assist in designing safe-to-eat drinks, meals, and medicines for many who have hassle swallowing.
Signing Off from Southern Sky Submit
The Darkish Power Survey has accomplished a six-year observing run that can put our cosmology fashions to essentially the most stringent take a look at but, as reported on the American Astronomical Society winter assembly.
Q&A: Analyzing a Cell’s Form-Shifting “Bones”
Biophysicist Jennifer Ross hopes to search out the principles that govern how cells restructure and self-repair, with the aim of making new supplies that do the identical factor.
Extra Options »
Nobel Prize in Physics 2018
Prize acknowledges Arthur Ashkin, Gérard Mourou, and Donna Strickland for growing laser instruments which have led to new biophysics experiments and medical applied sciences.
The place Are They Now?
For our ten-year anniversary, the editors of Physics look again at a few of the previous analysis we now have lined and ask: What’s turn into of it?
Extra Bulletins »