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2d
accepted borel measurable functions and measurable functions
2d
comment borel measurable functions and measurable functions
Thanks! Very neat construction!
2d
comment borel measurable functions and measurable functions
@PhoemueX Thanks, that solves the problem!
Mar
25
asked borel measurable functions and measurable functions
Mar
13
awarded  Yearling
Feb
7
accepted boundary of the support of a continuous function
Feb
7
comment boundary of the support of a continuous function
Thanks. That's a nice example!
Feb
7
asked boundary of the support of a continuous function
Nov
7
comment minimize p norm of f+c
Never mind. I've already found a counter example. $e^x$ in $L^4$ doesn't follow this rule.
Nov
7
asked minimize p norm of f+c
Sep
21
revised determinant in terms of quadratic form evaluated at a point
deleted 605 characters in body; edited tags; edited title
Sep
21
awarded  Citizen Patrol
Sep
21
comment determinant in terms of quadratic form evaluated at a point
@copper.hat I sincerely apologize for that. I am deleting this post.
Sep
21
comment determinant in terms of quadratic form evaluated at a point
@WillJagy I am not trying to offend any of you. Perhaps what I said is not so polite. I apologize for that. Also to copper.hat. I can't at two users in one comment.
Sep
21
comment determinant in terms of quadratic form evaluated at a point
This is not what I asked anyway. Towards the end, if you note that $A^*=det(A)A^{-1}$ you just got what I said in my post "A simple calculation reveals" .
Sep
21
comment determinant in terms of quadratic form evaluated at a point
@WillJagy $n=1$ doesn't yield anything interesting. By positive definite I meant symmetric positive definite. Personally, I don't believe there is a relationship. If one just take $b$ to be an eigenvector, then the quantity given above would just be the product of the $n-1$ remaining eigenvalues. Since determinant is the product of $n$ eigenvalues, there is no guarantee that one might be bigger than the other. It all depends on whether the last eigenvalue is bigger or smaller than 1. The person who told me this seemed very certain. So I decided to ask in case people here have seen this before.
Sep
21
comment determinant in terms of quadratic form evaluated at a point
@WillJagy Do you know that such a formula exists or are you just making a general comment?
Sep
21
asked determinant in terms of quadratic form evaluated at a point
Sep
6
awarded  Tumbleweed
Aug
30
asked Does symmetric decreasing rearrangement of a smooth function preserves smoothness?