Category Archives: Geometry

Or Ordentlich, Oded Regev and Barak Weiss: New bounds for Covering Density!

Barak Weiss lectured about his breakthrough results with Or Ordentlich, and Oded Regev, at a Simons Institute workshop: Lattices: Geometry, Algorithms and Hardness. It is a famous problem what is the densest (or, most efficient) packing of unit balls in Euclidean … Continue reading

Posted in Combinatorics, Computer Science and Optimization, Geometry | Tagged , , | 2 Comments

To cheer you up in complicated times – A book proof by Rom Pinchasi and Alexandr Polyanskii for a 1978 Conjecture by Erdős and Purdy!

Things do not look that good, and these are difficult times. But here on the blog we have plenty of things to cheer you up and assure you. And today we point to two book proofs — two book proofs … Continue reading

Posted in Combinatorics, Geometry, What is Mathematics | Tagged , | 8 Comments

Do Not Miss: Abel in Jerusalem, Sunday, January 12, 2020

From left: Christopher Hacon, Claire Voisin, Ulrike Tillmann,  François Labourie Update: This was a great event with four great inspiring talks. Abel in Jerusalem, January 12, 2020 The Einstein Institute of mathematics is happy to host the Abel in Jerusalem Conference “Abel in … Continue reading

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Gil Bor, Luis Hernández-Lamoneda, Valentín Jiménez-Desantiago, and Luis Montejano-Peimbert: On the isometric conjecture of Banach

Stefan Banach and one of his famous quotes. Is it really true? A commentator (troll?) named Gina tried to challenge it in a heated discussion over the n-Category cafe. This post briefly describes a May 2019 paper On the isometric conjecture … Continue reading

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Abel in Jerusalem – SUNDAY, January 12, 2020, and other events

Update: Boris Solomyak’s birthday conference (January 13-14, Bar-Ilan University)is now added. I would like to report on seven eight nine ten mathematical events taking place in Jerusalem, the Tel Aviv area, and Haifa in the next few weeks. (Probably I … Continue reading

Posted in Algebra, Analysis, Combinatorics, Computer Science and Optimization, Conferences, Geometry, Updates | Tagged , , , | 1 Comment

Old lecture notes by Alex Zabrodsky

The next post will announce several mathematical events taking place in the next few weeks in Israel. One of these events is the Zabrodsky lectures at the Hebrew University of Jerusalem, that are given this year by Paul Seidel, starting … Continue reading

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Starting today: Kazhdan Sunday seminar: “Computation, quantumness, symplectic geometry, and information”

Sunday, 27 October, 2019 – 14:00 to 16:00 Repeats every week every Sunday until Sat Feb 01 2020 Location: Ross 70 See also: Seminar announcement; previous post Symplectic Geometry, Quantization, and Quantum Noise. The Google supremacy claims are discussed (with … Continue reading

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Alef’s corner: Bicycles and the Art of Planar Random Maps

The artist behind Alef’s corner has a few mathematical designs and here are two new ones. (See Alef’s  website offering over 100 T-shirt designs.)   which was used for the official T-shirt for Jean-François Le Gall’s birthday conference. See also … Continue reading

Posted in Art, Combinatorics, Geometry, Probability | Tagged | Leave a comment

Mohammad Ghomi and Joel Spruck settled the Cartan-Hadamard conjecture!

Greetings from Oberwolfach from a great conference on algebraic, geometric, and topological combinatorics. Stay tuned for more pictures and updates from Oberwolfach and CERN, and also in case you did not see it already here is the link to the … Continue reading

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Imre Bárány: Limit shape

Limit shapes are fascinating objects in the interface between probability and geometry and between the discrete and the continuous. This post is kindly contributed by Imre Bárány. What is a limit shape? There are finitely many convex lattice polygons contained … Continue reading

Posted in Combinatorics, Convexity, Geometry, Guest blogger, Probability | Tagged , | 4 Comments