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Dec 2, 2020 at 16:08 vote accept lamlame
Nov 30, 2020 at 20:18 history closed Joonas Ilmavirta
Desiderius Severus
Eric Peterson
Mark Wildon
Alexandre Eremenko
Needs details or clarity
Nov 22, 2020 at 23:43 answer added R W timeline score: 2
Nov 22, 2020 at 22:49 comment added Michael Engelhardt I still don't get why you assert that "isotropic random vectors don't have the property of isotropy". The contradiction doesn't seem to be between these notions of isotropy, but between the given definition of an isotropic random vector and a mistaken interpretation of that definition in a post on math.stackexchange.com.
Nov 22, 2020 at 21:11 answer added Carlo Beenakker timeline score: 1
Nov 22, 2020 at 21:11 comment added lamlame Okay thank you. In the other post the OP asked if the specific translation X-EX is isotropic. This would be true if EX = 0, but since the answer was this translation did not preserve isotropy presumably EX=/=0. So there isn't "sameness in all directions", even with respect to the origin, unless their answer was wrong.
Nov 22, 2020 at 21:06 review Close votes
Nov 30, 2020 at 20:18
S Nov 22, 2020 at 20:59 history suggested RobPratt
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Nov 22, 2020 at 20:30 comment added Malkoun Well, I think they mean "isotropic" as "the same in all directions", roughly speaking, but with respect to the origin only. In the other post, the OP asked whether translation preserves isotropy and it turns out the answer is no. But $\mathbb{R}^n$ is not just an affine space, it also has a "special point", namely the origin. Your question was about terminology, so I hope my somewhat vague comment helps.
Nov 22, 2020 at 20:27 review Suggested edits
S Nov 22, 2020 at 20:59
Nov 22, 2020 at 20:23 comment added lamlame I added a link. If a random vector was to some amount uniform in different directions, it should at the least have expectation $0$. (If it wasn't rotate the vector to get a contradiction).
Nov 22, 2020 at 20:19 history edited lamlame CC BY-SA 4.0
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Nov 22, 2020 at 20:08 comment added Michael Engelhardt It's hard to make sense of your question. You assert that an isotropic object doesn't have the property of isotropy, without explaining what you mean by "property of isotropy".
Nov 22, 2020 at 19:58 review First posts
Nov 22, 2020 at 20:08
Nov 22, 2020 at 19:53 history edited lamlame CC BY-SA 4.0
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Nov 22, 2020 at 19:48 history asked lamlame CC BY-SA 4.0