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Aug 13, 2015 at 13:29 comment added BS. @Ian : ok! I was under the wrong impression that you were sketching the proof of precompactness (it was kind of obvious to me that a precompact metric space is bounded, which is what you prove). Sorry.
Aug 13, 2015 at 5:48 comment added Ian Agol By the precompactness theorem - see the third paragraph.
Aug 10, 2015 at 21:19 comment added BS. Sorry Ian, maybe I'm being thick, but I don't understand why you can assume $g_i$'s and $h_i$'s are $\delta$-close among themselves. Could you elaborate ?
Apr 27, 2015 at 20:47 comment added Ian Agol @SelimG: Yes, you're essentially correct. In fact, for a fixed $M$, there are boundedly many curves of bounded length. So a subsequence will preserve the homotopy class of $\gamma$. I should fix the answer to reflect this.
Apr 27, 2015 at 16:32 comment added Selim G Dear Ian, I checked in detail this morning your argument. There is one thing which is not clear to me(in the last part). Two metric on $M$ are said to be $C$-close if there is a diffeomorphism $f$ of $M$ such that both $f$ and $f^{-1}$ are $e^C$-Lipschitz, but to get the bound on $L_g(\gamma)$ one would would have to be sure that $f$ preserves the class of $\gamma$. We might need here something like the finiteness of the mapping class group of $M$ to conclude right ?
Apr 25, 2015 at 10:18 comment added Selim G Thank you Ian, Belgradek's paper answer the very first question I had in mind, namely how different can two negatively curved metric be on the same underlying manifold.
Apr 25, 2015 at 10:16 vote accept Selim G
Apr 23, 2015 at 16:12 history edited Ian Agol CC BY-SA 3.0
Added more exposition.
Apr 23, 2015 at 5:22 history answered Ian Agol CC BY-SA 3.0