7 research outputs found
Random runners are very lonely
Suppose that runners having different constant speeds run laps on a
circular track of unit length. The Lonely Runner Conjecture states that, sooner
or later, any given runner will be at distance at least from all the
other runners. We prove that, with probability tending to one, a much stronger
statement holds for random sets in which the bound is replaced by
\thinspace . The proof uses Fourier analytic methods. We also
point out some consequences of our result for colouring of random integer
distance graphs
Correlation among runners and some results on the Lonely Runner Conjecture
The Lonely Runner Conjecture was posed independently by Wills and Cusick and
has many applications in different mathematical fields, such as diophantine
approximation. This well-known conjecture states that for any set of runners
running along the unit circle with constant different speeds and starting at
the same point, there is a moment where all of them are far enough from the
origin. We study the correlation among the time that runners spend close to the
origin. By means of these correlations, we improve a result of Chen on the gap
of loneliness and we extend an invisible runner result of Czerwinski and
Grytczuk. In the last part, we introduce dynamic interval graphs to deal with a
weak version of the conjecture thus providing some new results.Comment: 18 page
Lonely runners in function fields
The lonely runner conjecture, now over fifty years old, concerns the
following problem. On a unit length circular track, consider runners
starting at the same time and place, each runner having a different constant
speed. The conjecture asserts that each runner is lonely at some point in time,
meaning distance at least from the others. We formulate a function field
analogue, and give a positive answer in some cases in the new setting
Computing the covering radius of a polytope with an application to lonely runners
We are concerned with the computational problem of determining the covering
radius of a rational polytope. This parameter is defined as the minimal
dilation factor that is needed for the lattice translates of the
correspondingly dilated polytope to cover the whole space. As our main result,
we describe a new algorithm for this problem, which is simpler, more efficient
and easier to implement than the only prior algorithm of Kannan (1992).
Motivated by a variant of the famous Lonely Runner Conjecture, we use its
geometric interpretation in terms of covering radii of zonotopes, and apply our
algorithm to prove the first open case of three runners with individual
starting points.Comment: 22 pages, 4 tables, 2 figures, revised versio