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+--- Thread: Explaining dark matter with more dimensions + Is there a hidden quantum reality? (/thread-10613.html)
Explaining dark matter with more dimensions + Is there a hidden quantum reality? - C C - Jul 9, 2021
Is there a hidden quantum reality underlying what we observe?
https://www.forbes.com/sites/startswithabang/2021/07/09/ask-ethan-is-there-a-hidden-quantum-reality-underlying-what-we-observe/
EXCERPT: . . . The thing we always have to remember, when it comes to the physical Universe, is that no matter how certain we are of our logical reasoning and our mathematical soundness, the ultimate arbiter of reality comes in the form of experimental results. When you take the experiments that we’ve performed and try to deduce the rules that govern them, you must obtain a self-consistent framework. Although there are a myriad of interpretations of quantum mechanics that are equally as successful at describing reality, none have ever disagree with the original (Copenhagen) interpretation’s predictions. Preferences for one interpretation over another — which many possess, for reasons I cannot explain — amount to nothing more than ideology.
If you wish to impose an additional, underlying set of hidden variables that truly governs reality, there’s nothing preventing you from postulating their existence. What the Kochen-Specker theorem tells us, though, is that if those variables do exist, they do not pre-determine the values revealed by experimental outcomes independently of the quantum rules we already know. This realization, known as quantum contextuality, is now a rich area of research in the field of quantum foundations, with implications for quantum computing, particularly in the realms of speeding up computations and the quest for quantum supremacy. It isn’t that hidden variables can’t exist, but rather that this theorem tells us that if you wish to invoke them, here’s what sort of finagling you have to do.
No matter how much we might dislike it, there’s a certain amount of “weirdness” inherent to quantum mechanics that we simply can’t get rid of. You might not be comfortable with the idea of a fundamentally indeterminate Universe, but the alternative interpretations, including those with hidden variables, are, in their own way, no less bizarre. (MORE - missing details)
Can we explain dark matter by adding more dimensions to the universe?
https://www.livescience.com/self-interacting-dark-matter-higher-dimensional-universe.html
EXCERPTS: . . . "We live in an ocean of dark matter, yet we know very little about what it could be," Flip Tanedo, an assistant professor of physics and astronomy at the University of California Riverside, said in a statement.
Every attempt to explain dark matter using known physics has come up short, and so Tanedo and his collaborators are developing exotic models that might better match observations. [...] Even though cosmologists don't know the identity of dark matter, they do know some of its properties.
All observations indicate that the dark matter is made of some new kind of particle, previously unknown to physics. That particle floods each and every galaxy, accounting for more than 80% of their mass. That particle must not interact with light very much, if at all (otherwise we would have seen it by now in astronomical observations). And it must not interact with normal matter very much, if at all (otherwise we would have seen it in particle collider experiments).
Taking these properties together, cosmologists are able to build sophisticated computer simulations [...] However, these still-underperforming models are based on known physical interactions that take place via one of the four fundamental forces of nature. ... But if simply exporting known physics into the realm of dark matter is coming up short, maybe it's time to look at completely new forces.
Tanedo and his collaborators tried to do just that, and described their work in a paper published June 1 in the Journal of High Energy Physics. Their new model greatly expands possible models of interacting dark matter, allowing for unknown forces to come into play.
[...] Tanedo's approach to dark matter involves two surprising features. One, instead of a single force that connects dark matter particles, the model includes an infinite spectrum of new forces all working together. Two, the model requires an extra dimension to the universe, so a four-dimensional space.
[...] "My research program targets one of the assumptions we make about particle physics: that the interaction of particles is well-described by the exchange of more particles," Tanedo said in the statement. "While that is true for ordinary matter, there's no reason to assume that for dark matter. Their interactions could be described by a continuum of exchanged particles rather than just exchanging a single type of force particle."
[...] This modification to the self-interaction among dark matter particles allowed the researchers to build simulations that match observations of small galaxies, giving them a "core"-like dark matter profile, rather than the "cuspy" one seen in traditional dark matter models... (MORE - missing details)