# About why the Dirac-delta is not belong to H^-1 or H^1?

**URL:** https://community.freefem.org/t/about-why-the-dirac-delta-is-not-belong-to-h-1-or-h-1/1181
**Category:** General Discussion
**Created:** [August 29, 2021, 6:14am UTC](https://community.freefem.org/t/about-why-the-dirac-delta-is-not-belong-to-h-1-or-h-1/1181 "2021-08-29T06:14:12Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![HGH](https://avatars.discourse-cdn.com/v4/letter/h/3be4f8/32.png) [@HGH](https://community.freefem.org/u/HGH)
#### Post date: [August 29, 2021, 6:14am UTC](https://community.freefem.org/t/about-why-the-dirac-delta-is-not-belong-to-h-1-or-h-1/1181/1 "2021-08-29T06:14:13Z")

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Hi FreeFEM++ developers and users

I have a question, About why the Dirac-delta is not belong to H^-1 or H^1?  
Who can explain it?