ProblÃ¨mes & Conjectures
Coloring - Hoffman-Singleton packing - Seymour's 2nd Neighborhood Conjecture - Sumner's Universal Tournament Conjecture - Caccetta-H?ggkvist Conjecture - Zhang's Hamiltonian weight conjecture - Bermond's Conjecture - Induced forests in planar graphs - cyclic edge-connectivity of planar graphs - Tutte's 3-flow Conjecture (& 4 5) - etc.
Wall's k - The 4-move - The Grid Conjecture - The additivity issue - The X-moves
P versus NP, The Hodge Conjecture, The Riemann Hypothesis, Yang-Mills Existence and Mass Gap, Navier-Stokes Existence and Smoothness, The Birch and Swinnerton-Dyer Conjecture
There are three levels of problems: High School, Advanced, and Challenge.
University of Mississippi's School of Education
Some Research Problems in Commutative Algebra
Flows on Graphs, Choosability for Ax=y, Edge-Decompositions of Graphs, Other Problems
From the SIAM Activity Group Newsletter in Discrete Mathematics
These problems and conjectures concern the determination of properties of families of graphs.
Workshop on Satisfiability 1996
The institute is best know for its establishment on May 24, 2000 of the Millennium Prize Problems.
Marek KORDOS Institute of Mathematics, Warsaw University
Stefan Banach was the first to enter a problem to the Book on July 17 of 1935. The last problem, problem 193, was due to Hugo Steinhaus and it bears the date of May 31, 1941. The total number of problems was actually greater than 193, since the numeration used to be repetitive. For instance, there was problem number 10.1, 15.1 or 17.1. Most problems have been solved, though not all of them. In some cases the solution was not a mere intellectual exercise or sport, for it marked the beginning of a new direction of research.
Venn Diagram Survey Frank Ruskey
This is a collection of open problems in Discrete Mathematics which are currently being researched by members of the DIMACS community. These problems are easily stated, require little mathematical background, and may readily be understood and worked on by anyone who is eager to think about interesting and unsolved mathematical problems.
This theoretical computer sience problem was published 1946 by Emil Post in Bulletins of the American Math. Society -- Vol. 53. He proved the undeciablility for the general case and hence for the first time introduced a concrete combinatorial puzzle, which was not recursive solvable in the Turing computational model.
-- Challenges to the Unsolved Problems in Number Theory --
1. Cerny's conjecture 2. The star-height problem 3. A Schreier formula for the free monoid 4. Concatenation hierarchies
Here are some problems I tried but could not solve. They reflect only my personal taste and (lack of) mathematical abilities. I tried to avoid well-known questions here, so, despite I spent a lot of time on, say, the two-weight problem for the Hilbert transform (with very limited success), I'm not putting the corresponding question here: it is very well known without my advertising it on my web page. At last, keep in mind that this page is permanently under construction.
This is the memorial site for Gian-Carlo Rota, 1932-1999.
This site is maintained by Bill Chen
of the Combinatorics Net
POINTS DE VUE
A $7 million offer has created a buzz in the esoteric world of maths. Anjana Ahuja reports
PROBLÈMES - PROBLEMS
This is my current "Most Wanted" list of elementary unsolved
The "Erdos-Strauss conjecture" (ESC) is the statement that for any integer n > 1 there are integers a, b, and c with 4/n = 1/a + 1/b + 1/c, a > 0, b > 0, c > 0.
Problems & Puzzles: Puzzles
is an old unsolved problem in number theory.
M.M.Sheremeta O.B.Skaskiv M.O.Ghirnyk
This page lists a variety of questions in combinatorics that I believe are open questions and to which I would be interested in knowing the answer.
Zsolt Tuza May 2001 BRICS
The sum of the proper divisors is i(n) = sigma(n) - n
...This was first published by the Belgian mathematician EugÃ¨ne Catalan in the year 1888. Leonard Eugene Dickson extended the so called Catalan conjecture: "Each aliquot sequence ends in a prime, in a perfect number or in an aliquot cycle"...
Discussion of open problems in mathematical logic
Community Interest Recursion Theory Set Theory Model Theory Proof Theory
EXEMPLES - EXAMPLES
Recherches de sous-chaÃ®nes du mot infini de Kolakoski K = 121121221221121122121121221121121221221121 qui est autodescriptif. Quelques problÃ¨mes ouverts (formule close, sous-chaÃ®nes ...)
DOCUMENTS - PAPERS
Daniel A. Klain Department of Mathematical Sciences University of Massachusetts
JOURNAUX - LETTERS
QUESTIONS - FAQ
The Sci.Math FAQ Team. Editor: Alex LÃ³pez-Ortiz
LIENS - LINKS