36 research outputs found
On sub-determinants and the diameter of polyhedra
We derive a new upper bound on the diameter of a polyhedron P = {x \in R^n :
Ax <= b}, where A \in Z^{m\timesn}. The bound is polynomial in n and the
largest absolute value of a sub-determinant of A, denoted by \Delta. More
precisely, we show that the diameter of P is bounded by O(\Delta^2 n^4 log
n\Delta). If P is bounded, then we show that the diameter of P is at most
O(\Delta^2 n^3.5 log n\Delta).
For the special case in which A is a totally unimodular matrix, the bounds
are O(n^4 log n) and O(n^3.5 log n) respectively. This improves over the
previous best bound of O(m^16 n^3 (log mn)^3) due to Dyer and Frieze
On Sub-determinants and the Diameter of Polyhedra
We derive a new upper bound on the diameter of a polyhedron P = { x ∈ R n : A x ≤ b } , where A ∈ Z m × n . The bound is polynomial in n and the largest absolute value of a sub-determinant of A , denoted by Δ . More precisely, we show that the diameter of P is bounded by O ( Δ 2 n 4 log n Δ ) . If P is bounded, then we show that the diameter of P is at most O ( Δ 2 n 3.5 log n Δ ) . For the special case in which A is a totally unimodular matrix, the bounds are O ( n 4 log n ) and O ( n 3.5 log n ) respectively. This improves over the previous best bound of O ( m 16 n 3 ( log m n ) 3 ) due to Dyer and Frieze (Math Program 64:1-16, 1994)
A Note on Non-Degenerate Integer Programs with Small Sub-Determinants
The intention of this note is two-fold. First, we study integer optimization
problems in standard form defined by and present
an algorithm to solve such problems in polynomial-time provided that both the
largest absolute value of an entry in and are constant. Then, this is
applied to solve integer programs in inequality form in polynomial-time, where
the absolute values of all maximal sub-determinants of lie between and
a constant
Primitive Zonotopes
We introduce and study a family of polytopes which can be seen as a
generalization of the permutahedron of type . We highlight connections
with the largest possible diameter of the convex hull of a set of points in
dimension whose coordinates are integers between and , and with the
computational complexity of multicriteria matroid optimization.Comment: The title was slightly modified, and the determination of the
computational complexity of multicriteria matroid optimization was adde
FPT-algorithms for some problems related to integer programming
In this paper, we present FPT-algorithms for special cases of the shortest
lattice vector, integer linear programming, and simplex width computation
problems, when matrices included in the problems' formulations are near square.
The parameter is the maximum absolute value of rank minors of the corresponding
matrices. Additionally, we present FPT-algorithms with respect to the same
parameter for the problems, when the matrices have no singular rank
sub-matrices.Comment: arXiv admin note: text overlap with arXiv:1710.00321 From author:
some minor corrections has been don