Note on a min-max problem of leo moser

Note on a min-max conjecture of Woodall

On the max min vertex cover Problem

We address the max min vertex cover problem, which is the maximization version of the well studied min independent dominating set problem, known to be NP-hard and highly inapproximable in polynomial time. We present tight approximation results for this problem on general graphs, namely a polynomial approximation algorithm which guarantees an n approximation ratio, while showing that unless P = ...

A Min-max Problem on Roots of Unity

Abstract. The worst-case residual norms of the GMRES method for linear algebraic systems [3] can, in case of a normal matrix, be characterized by a min-max approximation problem on the matrix eigenvalues. In [2] we derive a lower bound on this min-max value (worst-case residual norm) for each step of the GMRES iteration. We conjecture that the lower bound and the min-max value agree up to a fac...

A note on systems with max-min and max-product constraints

We consider a system A ◦ x b, where A ∈ Rm×n + is a non-negative matrix and b ∈ R+ is a non-negative vector over the n-dimensional variable l x u, where l, u ∈ R+ are lower and upper bounds, respectively, and ◦ is either a max–min or a maxproduct composition. It is shown that the set of minimal solutions of such systems can be computed in incremental quasi-polynomial time. © 2008 Elsevier B.V. ...

A Problem of Leo Moser About Repeated Distances on the Sphere

PAUL ERD%: I was born on March 26, 1913. My parents were both mathematics teachers and I learned a great deal of elementary mathematics from them. I received my Ph.D. in 1934 with Professor L. Fejir. I was in Manchester with Professor Mordell from 1934-38 and from 1938 to 1954 I was in the United States. Since then I have constantly travelled around the world: Hungary, the Anglo-Saxon countries...