Jonny Evans
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Registered User
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Lecturer at University College London. Thinking about symplectic topology.
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May 6 |
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Homeomorphism between base of conifolds and spheres That's handy to know (someone should write a dictionary). Hopefully the term "link of a singularity" will help you if you need to search the mathematical literature for this kind of stuff in future. |
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May 6 |
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Homeomorphism between base of conifolds and spheres You're welcome. Indeed, the fact that SO(3) acts freely on the unit cotangent bundle is another way to see that the unit cotangent bundle is diffeomorphic to RP^3. |
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May 6 |
accepted | Homeomorphism between base of conifolds and spheres |
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May 6 |
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Homeomorphism between base of conifolds and spheres Also, I would call X the link of the singularity rather than the base. |
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May 6 |
answered | Homeomorphism between base of conifolds and spheres |
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Apr 3 |
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Is there an effective way to calculate K-theory using Morse functions? "Flow data" would be a better description. You need to know stuff like the homotopy type of the attaching map of the cell. Even for Morse homology you need flow data for the differential. I seem to recall that Cohen-Jones-Segal explain what you would need to reconstruct the stable homotopy theory in terms of manifolds of flow-lines. They pick this case because it's all you can hope to recover in Floer theory - having infinite-dimensional stable/unstable manifolds means that the "homotopy type of the attaching map" wouldn't be very interesting even if it made sense. |
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Apr 3 |
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Is there an effective way to calculate K-theory using Morse functions? I always wanted to know the answer to this question, ever since reading Cohen-Jones-Segal: "Floer's infinite dimensional Morse theory and homotopy theory" where they construct the flow category Dylan Wilson mentioned. You could ask the same question about your favourite generalised cohomology theory. |
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Feb 12 |
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Mathematicians whose works were criticized by contemporaries but became widely accepted later @Thomas Riepe: Surely this disregard was about the value of the work, not its correctness? Or by "nonsense" do you mean "abstract nonsense"? |
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Feb 12 |
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Mathematicians whose works were criticized by contemporaries but became widely accepted later Did anyone ever really think that about Grothendieck? I suspect not. |
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Feb 7 |
answered | Discovering and selecting conferences |
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Jan 16 |
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Ricci flat-scalar flat Trace(A)=0 does not imply A=0. |
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Jan 11 |
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on the density of hypersurfaces in complex projective spaces The world is full of people who will think things are naive, but don't let that put you off: you ask questions for your sake, not for their sake. And often they're wrong anyway. |
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Jan 11 |
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on the density of hypersurfaces in complex projective spaces I wouldn't say it's naive, it seems like a reasonable idea that high degree hypersurfaces get complicated and fill up space. But as with all good reasonable ideas, it takes some effort to make sense of it. |
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Jan 11 |
accepted | on the density of hypersurfaces in complex projective spaces |
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Jan 11 |
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on the density of hypersurfaces in complex projective spaces Indeed, that was my first thought. I think by "the expected quantity must go to zero" the OP wanted an upper bound decreasing in the degree (which there cannot be unless you impose further conditions like epsilon-transversality). |
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Jan 10 |
answered | on the density of hypersurfaces in complex projective spaces |
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Jan 7 |
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New grand projects in contemporary math Thanks, I've edited accordingly. |
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Jan 7 |
revised |
New grand projects in contemporary math Edited as per comments |
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Jan 4 |
awarded | ● Nice Answer |
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Jan 2 |
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New grand projects in contemporary math I love that book! Recent work of Seidel (arxiv.org/abs/0704.2055) and McLean (arxiv.org/abs/1109.4466) explores such questions in the context of symplectic and contact topology. |
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Jan 2 |
answered | New grand projects in contemporary math |
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Dec 31 |
answered | Old books still used |
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Dec 30 |
revised |
Applications of Floer homology Fixed typos and added an application |
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Dec 28 |
accepted | Applications of Floer homology |
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Dec 26 |
answered | Applications of Floer homology |
