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May 6, 2016 at 18:37 vote accept Eckhard
May 6, 2016 at 18:37
Jan 8, 2013 at 17:32 comment added Suvrit @Eckhard: Sorry for the confusion; indeed, I meant $(1+a)^2$ and $2(1+a^2)$, not $\theta$ and $2\theta$ (stupid carry-over typo on my part!). thanks for catching this error! as soon as i get a chance, i'll edit my answer to reflect this correction.
Jan 7, 2013 at 22:04 comment added Eckhard @Suvrit: Is it possible that you meant to write in your analysis that $2^LM_L$ is comprised of the two numbers $\theta=(1+\alpha)^2$ and $2(1+\alpha^2)$, as opposed to $\theta$ and $2\theta$? This would lead to the bound $\sigma_1(K_L)\leq \frac{1}{2}\sqrt{3+2\alpha +3 \alpha ^2}$, which is tighter and indeed sharp for $\alpha=\pm 1$.
Jan 6, 2013 at 12:03 vote accept Eckhard
May 6, 2016 at 7:11
Dec 30, 2012 at 17:09 history edited Suvrit CC BY-SA 3.0
overhauled answer.
Dec 30, 2012 at 9:38 comment added Suvrit Certainly a closer characterization should be possible because the $K_L$ are column stochastic matrices that evolve with $L$ in a fairly regular way; if I get some time, I'll think a bit about this problem; otherwise, numerical experiments will offer a good "guess" that approximates the limit as a function of $\alpha$.
Dec 30, 2012 at 8:59 history edited Suvrit CC BY-SA 3.0
added one more sentence
Dec 29, 2012 at 22:32 comment added Eckhard @Suvrit: Thank you for your answer. Indeed, $\sigma_1(K_2(0))=\sqrt{3/4}$, and after that the sequence $(\sigma_1(K_L(0)))_L$ seems to be decreasing. Do you see a way to characterize the limit more precisely, as alluded to in your last sentence?
Dec 29, 2012 at 17:44 history answered Suvrit CC BY-SA 3.0