Algorithmic solvability of the lifting-extension problem
نویسندگان
چکیده
Let X and Y be finite simplicial sets (e.g. finite simplicial complexes), both equipped with a free simplicial action of a finite group G. Assuming that Y is dconnected and dimX ≤ 2d, for some d ≥ 1, we provide an algorithm that computes the set of all equivariant homotopy classes of equivariant continuous maps |X| → |Y |; the existence of such a map can be decided even for dimX ≤ 2d+1. For fixed G and d, the algorithm runs in polynomial time. This yields the first algorithm for deciding topological embeddability of a k-dimensional finite simplicial complex into R under the condition k ≤ 2 3n− 1. More generally, we present an algorithm that, given a lifting-extension problem satisfying an appropriate stability assumption, computes the set of all homotopy classes of solutions. This result is new even in the non-equivariant situation.
منابع مشابه
Algorithmic Properties of Polynomial Rings
In this paper we investigate how algorithms for computing heights, radicals, unmixed and primary decompositions of ideals can be lifted from a Noetherian commutative ring R to polynomial rings over R. It is a standard problem in mathematics to study which properties of a mathematical structure are preserved in derived structures. A typical result of this kind is the Hilbert Basis Theorem which ...
متن کاملA Generalization of the Meir-Keeler Condensing Operators and its Application to Solvability of a System of Nonlinear Functional Integral Equations of Volterra Type
In this paper, we generalize the Meir-Keeler condensing operators via a concept of the class of operators $ O (f;.)$, that was given by Altun and Turkoglu [4], and apply this extension to obtain some tripled fixed point theorems. As an application of this extension, we analyze the existence of solution for a system of nonlinear functional integral equations of Volterra type. Finally, we p...
متن کاملررسی شرط پیکارد در مسأله انتقال به سمت پائین در تعیین ژئوئید بدون استفاده از روش استوکس
The problem of downward continuation of the gravity field from the Earth’s surface to the reference ellipsoid arises from the fact that the solution to the boundary value problem for geoid determination without applying Stokes formula is sought in terms of the disturbing potential on the ellipsoid but the gravity observations are only available on the Earth’s surface. Downward continuation is a...
متن کاملSolvability of Systems of Polynomial Equations over Finite Algebras
We study the algorithmic complexity of determining whether a system of polynomial equations over a finite algebra admits a solution. We prove that the problem has a dichotomy in the class of finite groupoids with an identity element. By developing the underlying idea further, we present a dichotomy theorem in the class of finite algebras that admit a non-trivial idempotent Maltsev condition. Th...
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete & Computational Geometry
دوره 57 شماره
صفحات -
تاریخ انتشار 2017