Some Physicists See Signs of Cosmic Strings from the Big Bang | Hacker News Reader

Some Physicists See Signs of Cosmic Strings from the Big Bang

quantamagazine.org

71 pointstheafh21 comments

It's alluded to in the Quanta Mag article, but it's worth repeating the information from the NANOgrav discovery paper[0], as stated in the paper's abstract:

However, we find no statistically significant evidence that this process has quadrupolar spatial correlations, which we would consider necessary to claim a GWB detection consistent with General Relativity.

So I'm inclined to think that all the "explanation" papers are premature. It's an interesting (low-significance) signal in the data, but more data are needed.

[0] https://arxiv.org/abs/2009.04496

I had a thought today that entanglement between particles could be the result of strings wrapping around two quantum particles, and that pulling on the string would result in a motion on one quantum particle that is inversely enacted on the other.

The knot around each quantum particle would have to be an inverse of the other knot for this to work. In theory, this idea would also make the entanglement of N-particles possible. Although, it wouldn’t be obvious to determine since for every even number of entangled quantum particles it would look like log2(N) pairs of entangled quantum particles and with every odd number of entangled particles each odd set would look like an even set of entangled quantum particles with an additional particle reflecting some seemingly uncorrelated state.

I do not have a deep understanding of quantum mechanics but wanted to share because my ideas like this often die with the last thought. Although, I am doing an independent study on quantum computing this semester and have found it to be very stimulating.

I'm not sure what you mean by "an inverse of the other knot". If you mean an inverse with respect to the operation of a connected sum of knots, then note that knots do not have inverses with respect to this operation. ( https://en.wikipedia.org/wiki/Connected_sum#Connected_sum_of... )

But I'm guessing you mean something else by inverse. Like, maybe just the mirror image of the knot, if the knot is a chiral knot?

What you described reminds me of these two things (visually):

1. 6-dimensional Calabi-Yau manifolds with Ricci flatness https://vimeo.com/81756249

2. Hopf vibrations: https://juliahub.com/docs/Porta/4MpHD/0.1.1/_packagesource/f...

I wonder how this meshes, or clashes, with the recent reinvigoration of primordial black holes as dark matter candidates (versus non-interactive particles).

It’s really an exciting time in astronomy!

When most people see the word `string` in science, `string theory` comes to mind and maybe best to think of them as Space dendrites.

How self-similar in thinking so, from the cosmos, to the roots, to the nerves, to the brain.

Genuine curiousity. Do these mean strings from string theory.

Imagine some water freezing. This will often start from a nucleation point and spread out rapidly. If this hits another volume of water nearby that's doing the same thing, you might get a crack in the ice where they hit each other. This is kind of what cosmic strings are. As the universe is cooling and quantum fields undergo phase changes, various regions will spread out and the point where they collide can form a cosmic string. (This is all very theoretical and my explanation is rather vague and handwavy).

Intuitive description. Thanks!

From my understanding of the article, they aren't necessarily the same but could be related:

  Another more speculative possibility is that cosmic strings could come from the tiny vibrating strings of string theory. Some string theory models propose that strings could have grown to colossal proportions during the initial rapid expansion of the cosmos. Differences in the tension of these kinds of cosmic strings and in how string loops break away would create a unique gravitational-wave signature distinguishing them from other kinds.

https://en.wikipedia.org/wiki/Cosmic_string

Not far enough down the line to understand either theory but "string" is overloaded.

I'm confused, "It is expected that at least one string per Hubble volume is formed." (10^31 cubic light years.) ... one string per an observable universe?

Or am I not thinking clearly?

The observable universe is much larger than the hubble volume. I understand this to be due to changes in the rate or expansion of the universe over time, though I'm no astronomer myself.

The amount of "observable universes" would be at what number given that each one is a string? How many potential strings from the initial moment? Seems... just mind boggling.

Interesting - feels related to Sungchul Ji's work: https://www.mdpi.com/2078-2489/8/1/24 Waves as the Symmetry Principle Underlying Cosmic, Cell, and Human Languages

Waves being a unifying concept of communication (language). It's quite interesting and rooted in strong fundamentals. Take a look if you're curious! There's more recent work published that you may find elsewhere other than that paper linked.

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