<p>The answer to your question is affirmative. <em>In principle</em>, the Poincare invariance may be violated at cosmic scales. A possibility for this may be coming from theories more fundamental than Relativity and the Standard Model. 'More fundamental' may imply the string theory or another unified theory. The topic is being investigated by <a href="https://www.benefunder.com/technology-causes/alan-kostelecky/beyond-einstein-the-search-for-relativity-violations" rel="nofollow noreferrer">Alan Kostelecky</a> and his coauthors. For a popular outline of their research, see <a href="https://lorentz.sitehost.iu.edu/kostelecky/lay/04sciam.pdf" rel="nofollow noreferrer">this short article</a>.</p>

CC BY-SA 4.0
2023-03-21T00:26:36.480Z
2023-03-21T00:26:36.480Z
Michael_1812
<p>I have heard that some types of inhomogeneities and topological defects in cosmology have been proposed to be able to break fundamental symmetries of nature such as the Poincaré, Lorentz, diffeomorphism CPT, spatial/time translational (etc) symmetries. However, I have not been able to find any references about this. Is this true? Is there anything about this?</p>

CC BY-SA 4.0
2023-03-12T14:02:47.043Z
This is a bit broad and lacks clear context.  As a rule whenever you write "I heard...." in a stack exchange question, you need to say where you heard this, from whom.  If you can't remember - that is a problem, and one you probably need to fix first.  Where might you have heard this?  Have you been reading physics papers? Have you been watching TV programs about cosmology?  Might it be in a book, or in a conversation?
James K
CC BY-SA 4.0
2023-03-21T05:54:43.780Z
In a sense the question boils down to "do asymmetries ruin symmetries?", the answer to which is obviously "yes".  Perhaps the more interesting question is *why* would one want asymmetries, or suspect they exist?
zibadawa timmy
<cosmology><universe><space-time><big-bang-theory><early-universe>
Could inhomogeneities or topological defects break the fundamental symmetries of the Universe?
vengaq
# Could inhomogeneities or topological defects break the fundamental symmetries of the Universe?

(Asked by: username_0 on 2023-03-12)

I have heard that some types of inhomogeneities and topological defects in cosmology have been proposed to be able to break fundamental symmetries of nature such as the Poincaré, Lorentz, diffeomorphism CPT, spatial/time translational (etc) symmetries. However, I have not been able to find any references about this. Is this true? Is there anything about this?

**Tags:** cosmology, universe, space-time, big-bang-theory, early-universe

> **Comments:**
> **username_1**: This is a bit broad and lacks clear context.  As a rule whenever you write "I heard...." in a stack exchange question, you need to say where you heard this, from whom.  If you can't remember - that is a problem, and one you probably need to fix first.  Where might you have heard this?  Have you been reading physics papers? Have you been watching TV programs about cosmology?  Might it be in a book, or in a conversation?  
> **username_2**: In a sense the question boils down to "do asymmetries ruin symmetries?", the answer to which is obviously "yes".  Perhaps the more interesting question is *why* would one want asymmetries, or suspect they exist?  

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## 1 answers

### Answer by username_3 on 2023-03-21. Score: 1

The answer to your question is affirmative. *In principle*, the Poincare invariance may be violated at cosmic scales. A possibility for this may be coming from theories more fundamental than Relativity and the Standard Model. 'More fundamental' may imply the string theory or another unified theory. The topic is being investigated by [Alan Kostelecky](https://www.benefunder.com/technology-causes/alan-kostelecky/beyond-einstein-the-search-for-relativity-violations) and his coauthors. For a popular outline of their research, see [this short article](https://lorentz.sitehost.iu.edu/kostelecky/lay/04sciam.pdf).


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