If Creativity were anything but Random, Someone would have figured out the Algorithm by now. -- Dilbert

There are ten kinds of people in the world. Those who think in binary and those who don't. Joel Spencer

Joel Spencer

Professor, Computer Science and Mathematics Depts

Email: {lowercaselastname}@cims.nyu.edu

Department of Computer Science and Department of Mathematics
Courant Institute, New York University


Room 829, 251 Mercer St.
New York, NY 10012, U.S.A.
212-998-3219 (voice) 212-995-4124 (fax)


  • Vita--Selected Work (short form)
  • Vita--Publication List (long form)
  • Papers Description of selected papers. Vita and those papers in postscript.
  • Talks Slides for various talks.

    Course Information

    Spring 2014 I will teach Algebra II. Students must have taken Algebra I to register but it is NOT necessary that they took it from me and it is NOT necessary that they took it Fall 2013. Click here for more information. Students may email with queries at any time.

    The Erdos-Selberg Controversy

    Over 60 years ago a controversy erupted between Paul Erdos and Atle Selberg over the elementary proof of the Prime Number Theorem. Ernst Straus -- then a young mathematician at the scene -- wrote a description of the events. These have been published in Math Intelligencer, along with commentary by Ron Graham and myself, and a mathematical postscript by Carl Pomerance.

    click here for the article

    The Probabilistic Method -- Third Edition!

    Check out a sample material and table of contents of this book with Noga Alon.

    Click here for the frontcover front cover with a great picture of Uncle Paul

    Click here for a richgetricher new Probabilistic Lens on Preferential Attachment

    Click here for a phasetransition new chapter on the Erdos-Renyi Phase Transition, with particular emphasis on the Critical Window.

    Click for more, available from archives here

    Click here
    Hannah1 Hannah2 Hannah3 Hannah4 for our most beautiful and most attentive reader. She's a fox! And, in strong competition: johanna and jazmin

    SPECIAL OFFER: Yes, your child (grandchild, niece, nephew, sibling) can have an Erdos Number of 1+\sqrt{-1}! Just send a photo of him/her absorbed in reading/playing/teething our book and I'll post it!


    Photo by MA

    Click for family photos, or a photo of Paul Erdos.

    Math News !

    Alantha Newman and Aleksandar Nikolov have solved the Beck Three Permutaion Problem. I had offered a prize of 100 USD for its resolution. Here are Alantha and Sasha with the prize jpg. They found three permutations of 1,...,n=3^t so that for any coloring of 1,...,n with +1,-1 in one of the permutations there will be a prefix whose sum has absolute value at least ct. The conjecture had been that there was an absolute constant K so that for any three permutations of any size n there would be such a coloring where in each permutation all prefixes would have sum in [-K,+K], and so the conjecture was disproved.

    Robin Moser, a student of Emo Welzl (ETH), has given an algorithmic implementation of the Lovasz Local Lemma. A rough explanation:

    postscript LaTeX pdf Click for Moser's paper with Gabor Tardos .

    Nikhil Bansal (at TU Eindhoven (Holland)) has given an algorithmic implementation of my result that given any n sets on n points there is a 2-coloring with all discrepencies less than 6 \sqrt{n}. I had long conjectured that no algorithm would exist. Semidefinite Programming is a key ingredient. His preprint, Constructive Algorithms for Discrepancy Minimization, is available on arXiv. Click for Bansal's paper . or here
    postscript LaTeX pdf for my own rough explanation. Even more recently Shachar Lovett and Raghu Meka ArXiV link . have come up with another argument, using a restricted Brownian Motion.

    High School MathCamps

    This is a topic dear to my heart. I am former chair of an AMS committee that gives grants to High School Math Camps. Click for camp information or for information about donations to a worthy cause!

    Some Links

    My Wikipedia page
    Erdos Wikipedia page
    Danielle (daughter)'s website
    Erdos Number Project
    Budapest Semesters in Mathematics
    Combinatorialist Rogue Gallery