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Is the Birkhoff von Neumann Theorem true for infinite matrices

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Clash Royale CLAN TAG #URR8PPP up vote 1 down vote favorite 1 The Birkhoff von Neumann Theorem states that any $ntimes n$ doubly stochastic matrix is a convex sum of permutation matrices. Is this true for $mathbbN times mathbbN$ matrices as well? (if yes, then can you give a reference?) linear-algebra discrete-mathematics game-theory share | cite | improve this question asked Jul 31 at 9:54 Yoav Rodeh 11 1 add a comment  |  up vote 1 down vote favorite 1 The Birkhoff von Neumann Theorem states that any $ntimes n$ doubly stochastic matrix is a convex sum of permutation matrices. Is this true for $mathbbN times mathbbN$ matrices as well? (if yes, then can you give a reference?) linear-algebra discrete-mathematics game-theory share | cite | improve this question asked Jul 31 at 9:54 Yoav Rodeh 11 1 add a comment  |  up vote 1 down vote favorite 1 up vote 1 down vote favorite 1

Find representatives for cosets. [closed]

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Clash Royale CLAN TAG #URR8PPP up vote 0 down vote favorite Let $G$ be a finite group and $H$ is a subgroup of $G$ where $[G:H]$ is $N$. Prove that there exists a subset $A$ of $G$ containing $N$ elements such that, $xH= yH $ implies $x=y$ and $Hx= Hy$ implies $x=y$ for all $x,y$ in $A$. This a problem from Basic Algebra by Jacobson. I dont have an idea how to start. Kindly provide hints. group-theory finite-groups share | cite | improve this question edited Jul 31 at 10:48 Alan Wang 4,088 9 30 asked Jul 31 at 10:04 tony 128 9 closed as off-topic by Derek Holt, John Ma, Mostafa Ayaz, amWhy, Isaac Browne Aug 1 at 0:47 This question appears to be off-topic. The users who voted to close gave this specific reason: " This question is missing context or other details : Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This in

Eigenvalues of $A +A^-1$

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Clash Royale CLAN TAG #URR8PPP up vote 0 down vote favorite 1 Knowing the eigenvalues of $A$, what we can say about the eigenvalues of $A+A^-1$? Is it true that $lambda_i,(A+A^-1) = lambda_i,A + frac1lambda_i,A$, where $lambda_i,A$ is the $i$-th eigenvalue of $A$? I ask this question after asking this question, due to the different opinion in the conversation in the comment. linear-algebra matrices eigenvalues-eigenvectors inverse share | cite | improve this question edited Jul 31 at 10:12 asked Jul 31 at 10:10 Alex 172 9 Consider $A$ already in Jordan normal form. Without loss, consider it is reduced to one block. What can be said about $A+A^-1$ in this situation? (Please always show the own work!) – dan_fulea Jul 31 at 10:13 Yes sorry, i just asked this question due to the comments in the conversation in a my previous question! – Alex Jul 31 at 10:16 1 The other question was involving the