Our universe has existed for 13.7 billion years and may seem stable, but some experiments suggest that it is in danger, walking on the edge of a very dangerous cliff, and it’s all because of a single instability. Fundamental Particles: of Higgs particle.
in New Research Me and my colleagues Physical letter BWe show that some models of the early universe, namely those involving light objects called primordial black holes, are unlikely to be correct because they would likely trigger the Higgs boson, ending the universe.
The Higgs particle Responsible for mass and interactions Of all the particles we know, the mass of a particle is a result of its elementary nature. Interacting with the fieldcalled the Higgs field. We know this field exists because the Higgs particle exists.
You can think of this field as a perfectly still bath of water that we bathe in. This field has identical properties throughout the universe, meaning that we observe the same masses and interactions throughout the universe. This uniformity has made it possible to observe and describe the same physical phenomena over thousands of years (as astronomers typically look backwards in time).
But the Higgs field is unlikely to be in its lowest possible energy state – it could theoretically change state in some places, dropping into a lower energy state – but if that happened, the laws of physics would change dramatically.
Such a change represents what physicists call a phase transition, which is what happens when water turns into steam, forming bubbles in the process. A phase transition in the Higgs field similarly creates lower-energy bubbles of space with entirely different physical properties.
In such a bubble, electrons’ masses would suddenly change, as would their interactions with other particles. The protons and neutrons that make up atomic nuclei and are made up of quarks would suddenly shift positions. Essentially, anyone who experienced such a change would likely not be able to report it.
Persistent risk
Recent measurements of particle masses Experimental results from CERN’s Large Hadron Collider (LHC) suggest that such an event is possible. But there’s no need to panic: it could happen just a few trillion years after we retire. For this reason, in the hallways of particle physics departments, we say that the universe is not unstable, but rather “metastable,” because the end of the world is not going to happen anytime soon.
There needs to be a good reason for the Higgs field to form bubbles: Quantum mechanics, the theory that governs the microcosm of atoms and particles, causes the Higgs’ energy to fluctuate constantly, and it is statistically possible (though unlikely) that the Higgs field will sometimes form bubbles, which is why it takes time.
However, if there is an external energy source, the story is different. Strong gravitational field or High Temperature Plasma (A form of matter made up of charged particles): The field can borrow this energy to form bubbles more easily.
Therefore, while there is no reason to expect that the Higgs field would form large numbers of bubbles today, a big question in the context of cosmology is whether the extreme environments just after the Big Bang could have caused such bubbles to appear.
However, when the universe was very hot, there was enough energy to help the Higgs bubble form. Thermal effects also stabilized the Higgs particle By modifying quantum properties. Therefore, this heat cannot cause the end of the universe, which is probably why we are still here.
Primordial black hole
But our new study shows that there is one source of heat that constantly drives such bubbling (without the stabilizing thermal effects seen early after the Big Bang): primordial black holes – a type of black hole that emerged from the collapse of an overly dense region of space-time in the early universe.
Unlike normal black holes, which form when stars collapse, primordial black holes are incredibly small and can weigh as little as a gram.
The existence of such light black holes is predicted by many theoretical models describing the evolution of the Universe shortly after the Big Bang, including: Some models of inflationThis suggests that the universe underwent a massive expansion after the Big Bang.
But proving their existence comes with a big caveat: in the 1970s, Stephen Hawking demonstrated through quantum mechanics that black holes slowly evaporate by emitting radiation through their event horizon (the point from which not even light can escape).
Hawking showed that black holes act like a heating source in the universe. Temperature is inversely proportional to massThis means that lighter black holes are much hotter and evaporate faster than heavier black holes.
In particular, if, as many models suggest, primordial black holes weighing less than a few hundred billion grams (10 billionth the mass of the Moon) formed in the early universe, they should have evaporated by now.
In The existence of the Higgs fieldSuch an object could then act like an impurity in a carbonated drink, providing energy through the effects of gravity (due to the black hole’s mass) and the surrounding temperature (due to Hawking radiation) to help the liquid form gas bubbles.
When a primordial black hole evaporates, They locally heat the universeThey evolve in the middle of hotspots that are much hotter than the surrounding Universe, but still cooler than the typical Hawking temperature. Using a combination of analytical calculations and numerical simulations, we show that the presence of these hotspots causes the Higgs field to constantly bubble up.
But we’re still here, which means that it’s highly unlikely that such objects ever existed – in fact, we should rule out any cosmological scenarios that predict their existence.
Unless, of course, we find evidence of the Higgs boson’s past existence in ancient radiation or gravitational waves. If we do, things might get even more exciting: it would suggest there’s something we don’t know about the Higgs boson that keeps it from bubbling away in the presence of an evaporating primordial black hole. This could actually be an entirely new particle or force.
Either way, it’s clear that there is still much to discover about the universe, from the smallest to the largest scales.
Lucien HutierPostdoctoral Researcher, King’s College London
This article is reprinted from conversation Published under a Creative Commons license. Original Article.
