Computing Integral Points in Convex Semi-algebraic Sets

نویسندگان

  • Leonid Khachiyan
  • Lorant Porkolab
چکیده

Let Y be a convex set in IR k deened by polynomial inequalities and equations of degree at most d 2 with integer coeecients of binary length l. We show that if Y \ ZZ k 6 = ;, then Y contains an integral point of binary length ld O(k 4). For xed k, our bound implies a polynomial-time algorithm for computing an integral point y 2 Y. In particular, we extend Lenstra's theorem on the polynomial-time solvability of linear integer programming in xed dimension to semideenite integer programming.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Algebraic boundaries of convex semi-algebraic sets

We study the algebraic boundary of a convex semi-algebraic set via duality in convex and algebraic geometry. We generalise the correspondence of facets of a polytope with the vertices of the dual polytope to general semi-algebraic convex sets. In this case, exceptional families of extreme points might exist and we characterise them semi-algebraically. We also give a strategy for computing a com...

متن کامل

Sweep Line Algorithm for Convex Hull Revisited

Convex hull of some given points is the intersection of all convex sets containing them. It is used as primary structure in many other problems in computational geometry and other areas like image processing, model identification, geographical data systems, and triangular computation of a set of points and so on. Computing the convex hull of a set of point is one of the most fundamental and imp...

متن کامل

Computing rational points in convex semi-algebraic sets and SOS decompositions

Let P = {h1, . . . , hs} ⊂ Z[Y1, . . . , Yk], D ≥ deg(hi) for 1 ≤ i ≤ s, σ bounding the bit length of the coefficients of the hi’s, and Φ be a quantifier-free P-formula defining a convex semi-algebraic set. We design an algorithm returning a rational point in S if and only if S ∩ Q 6= ∅. It requires σD ) bit operations. If a rational point is outputted its coordinates have bit length dominated ...

متن کامل

Analysis of the convergence rate for the cyclic projection algorithm applied to semi-algebraic convex sets

In this paper, we study the rate of convergence of the cyclic projection algorithm applied to finitely many semi-algebraic convex sets. We establish an explicit convergence rate estimate which relies on the maximum degree of the polynomials that generate the semi-algebraic convex sets and the dimension of the underlying space. We achieve our results by exploiting the algebraic structure of the ...

متن کامل

Steiner Type Formulae and Weighted Measures of Singularities for Semi-convex Functions

For a given convex (semi-convex) function u, defined on a nonempty open convex set Ω ⊂ Rn, we establish a local Steiner type formula, the coefficients of which are nonnegative (signed) Borel measures. We also determine explicit integral representations for these coefficient measures, which are similar to the integral representations for the curvature measures of convex bodies (and, more general...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1997