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visits member for 3 years, 3 months
seen Jun 5 at 21:31

Jul
2
awarded  Curious
Mar
19
awarded  Notable Question
Jan
22
awarded  Popular Question
May
15
awarded  Popular Question
Mar
28
accepted Characterizing the eigenvalues of matrix powers
Jan
10
asked convex optimization with inconsistent constraints
Oct
4
comment Characterizing the eigenvalues of matrix powers
take $k = 3$, how do you see that: $\prod^3 (A - b_iI) = A^3 - (b_1+b_2+b_3)A^2 + (b_1b_2 + b_2b_3 + b_1b_3)A - cI = A^3 - cI$?
Oct
3
asked Characterizing the eigenvalues of matrix powers
Oct
3
accepted On the eigenvalues of the square of a real matrix $A$
Oct
1
comment On the eigenvalues of the square of a real matrix $A$
right i know, im just trying to understand if the eigenvalues of $A^2$ are fully characterized by the eigenvalues of $A$, squared.
Oct
1
asked On the eigenvalues of the square of a real matrix $A$
Sep
28
accepted Intuitively (concretely actually) what happens when you multiply a matrix by its transpose?
Sep
28
comment Why does positive semi-definiteness in this inequality imply a convex set?
I see, thank you!
Sep
27
asked Intuitively (concretely actually) what happens when you multiply a matrix by its transpose?
Sep
27
accepted Why does positive semi-definiteness in this inequality imply a convex set?
Sep
27
comment Why does positive semi-definiteness in this inequality imply a convex set?
Yes that makes sense! The only part I don't see that well is the convexity of the quadratic form with $A$ posdef. Is the Hessian some multiple of $A$? I'm not sure how to differentiate it without expanding the expression first.
Sep
27
asked Why does positive semi-definiteness in this inequality imply a convex set?
Sep
27
accepted If a functions epigraph is a convex cone does this imply the function is convex?
Sep
27
comment If a functions epigraph is a convex cone does this imply the function is convex?
Ah yes, I see what you mean, thanks!
Sep
27
asked If a functions epigraph is a convex cone does this imply the function is convex?