Questions tagged [cosmic-string]

Questions about properties, dynamics and phenomenology of cosmic strings and superstrings.

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Gauge cosmic strings and large gauge transformations

I've been going around in circles (hah) about how gauged cosmic strings work (I've been using Preskill's notes for the most part). The global string scenario makes sense to me, since different points ...
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Does Goldstone theorem have anything to do with Cosmic string

Cosmic strings are formed due to topological defects during symmetry breaking phase transition in early universe. While Goldstone theorem states whenever we have continuous symmetry and it is ...
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How many cosmic strings are there in the Universe?

While researching cosmic strings, one often encounters terminology ranging from "scaling solutions" to "correlation lengths". As a newcomer, one of the first questions I have had is "how many cosmic ...
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Science of Kerr Black holes, can naked singularity form? Does it lead to another universe?

In the science fiction series, XeeLee Sequence, Stephen Baxter had used quite a lot of accurate physics in this hard science fiction. I was able to follow and determined which ones are true of our ...
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realistic string cosmology and cosmological constant

Apparently one can recover the Friedman Equations from String Cosmology where the critical dimensions is lowered (from 26) to four. If this is the case, is the bosonic partition function (~ ...
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Cosmic strings and ground state degeneracy in SSB

There are two conflicting perceptions that I have regarding the notion of ground state post-SSB. Consider the Higgs mechanism e.g. for the electroweak theory. On the one hand, we say that the vacuum ...
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What's the connection between cosmic strings and the strings hypothesized in string theory?

I read somewhere that Edward Witten, the (once) big hotshot of string theory, said that the discovery of cosmic strings (at the beginning of this Wikipedia article it is written: "Not to be confused ...
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149 views

What is a String Wall?

This question has nothing to do with sound waves, physical strings or walls... I am reading: https://arxiv.org/abs/1709.07091 It states "In the post-inflationary PQ symmetry breaking scenario, ...
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I've read a cosmic string can accelerate a mass. Can someone explain how it works?

In the book Brief Answers to the Big Questions: the final book from Stephen Hawking Hawking describes cosmic strings as follows; They are like rubber bands as they are under great tension, ...
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Candidates for cosmic strings

What are the observed candidates for cosmic strings (or other defects), that are not ruled out? With references if possible.
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Black hole and the cosmic string

For a regular black hole, the mass and energy of the black hole are identical(according to first law of black hole thermodynamics), but for a black hole with a cosmic string this is not satisfied. ...
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Basic question on Cosmic Strings

What is the typical size of Cosmic String Loops? If a loop is formed today, what are the restrictions on its size? I would like to know if there is a distribution of cosmic strings depending on its ...
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Gravitational lensing and cosmic strings

Say we have a straight cosmic string lying along the $z$-axis, with energy-momentum tensor $$T_{\mu\nu}=\mu\delta(x)\delta(y)\operatorname{diag}(1,0,0,-1)\tag{1}\label{1}$$ for some small positive ...
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Kalb-Ramond action and topological string radiation

Let's have simple scalar $\Phi$ action involves spontaneously symmetry breaking in a form $$ \tag 1 S = \int d^{4}x\left( |\partial_{\mu}\psi|^{2} + \psi^{2}|\partial_{\mu}\theta |^{2} - \frac{\lambda}...
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Global cosmic strings evolution

Recently I've read about axion string. It can be shown that the energy per unit length of the string located along $z$ axis is $$ \mu = 2 \pi f_{a}^{2}\ln\left( \frac{L}{\delta}\right), $$ where $L$ ...
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Cosmic string & grandfather paradox

Cosmic string was proposed several decades ago and there are claims stating it can span across the length of the universe and is less than an atom thick. How does a broken pieces of these cosmic ...