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Category Archives: Computer Science and Optimization
Symplectic Geometry, Quantization, and Quantum Noise
Over the last two meetings of our HU quantum computation seminar we heard two talks about symplectic geometry and its relations to quantum mechanics and quantum noise. Yael Karshon: Manifolds, symplectic manifolds, Newtonian mechanics, quantization, and the non squeezing theorem. … Continue reading
Lionel Pournin found a combinatorial proof for Sleator-Tarjan-Thurston diameter result
I just saw in Claire Mathieu’s blog ”A CS professor blog” that a simple proof of the Sleator-Tarjan-Thurston’s diameter result for the graph of the associahedron was found by Lionel Pournin! Here are slides of his lecture “The diameters of associahedra” … Continue reading
Posted in Combinatorics, Computer Science and Optimization, Convex polytopes
Tagged Associahedron, Lionel Pournin
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The Quantum Debate is Over! (and other Updates)
Quid est noster computationis mundus? Nine months after is started, (much longer than expected,) and after eight posts on GLL, (much more than planned,) and almost a thousand comments of overall good quality, from quite a few participants, my … Continue reading
The Quantum Fault-Tolerance Debate Updates
In a couple of days, we will resume the debate between Aram Harrow and me regarding the possibility of universal quantum computers and quantum fault tolerance. The debate takes place over GLL (Godel’s Lost Letter and P=NP) blog. The Debate Where were … Continue reading
Greg Kuperberg: It is in NP to Tell if a Knot is Knotted! (under GRH!)
Wolfgang Haken found an algorithm to tell if a knot is trivial, and, more generally with Hemion, if two knots are equivalent. Joel Hass, Jeff Lagarias and Nick Pippinger proved in 1999 that telling that a knot is unknotted is … Continue reading
Updates, Boolean Functions Conference, and a Surprising Application to Polytope Theory
The Debate continues The debate between Aram Harrow and me on Godel Lost letter and P=NP (GLL) regarding quantum fault tolerance continues. The first post entitled Perpetual motions of the 21th century featured mainly my work, with a short response by Aram. … Continue reading
A Discussion and a Debate
Heavier than air flight of the 21 century? The very first post on this blog entitled “Combinatorics, Mathematics, Academics, Polemics, …” asked the question “Are mathematical debates possible?” We also had posts devoted to debates and to controversies. A few days ago, … Continue reading
Fractional Sylvester-Gallai
Avi Wigderson was in town and gave a beautiful talk about an extension of Sylvester-Gallai theorem. Here is a link to the paper: Rank bounds for design matrices with applications to combinatorial geometry and locally correctable codes by Boaz Barak, Zeev … Continue reading
Posted in Combinatorics, Computer Science and Optimization, Geometry
Tagged Avi Wigderson, Codes, Greg Kuperberg, Sylvester-Gallai
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Ryan O’Donnell: Analysis of Boolean Function
Ryan O’Donnell has begun writing a book about Fourier analysis of Boolean functions and he serializes it on a blog entiled Analysis of Boolean Function. New sections appear on Mondays, Wednesdays, and Fridays. Besides covering the basic theory, Ryan intends to describe applications … Continue reading
Cup Sets, Sunflowers, and Matrix Multiplication
This post follows a recent paper On sunflowers and matrix multiplication by Noga Alon, Amir Spilka, and Christopher Umens (ASU11) which rely on an earlier paper Group-theoretic algorithms for matrix multiplication, by Henry Cohn, Robert Kleinberg, Balasz Szegedy, and Christopher Umans (CKSU05), … Continue reading
