1,444 research outputs found

    A simple proof for visibility paths in simple polygons

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    The purpose of this note is to give a simple proof for a necessary and sufficient condition for visibility paths in simple polygons. A visibility path is a curve such that every point inside a simple polygon is visible from at least one point on the path. This result is essential for finding the shortest watchman route inside a simple polygon specially when the route is restricted to curved paths

    Query-points visibility constraint minimum link paths in simple polygons

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    We study the query version of constrained minimum link paths between two points inside a simple polygon PP with nn vertices such that there is at least one point on the path, visible from a query point. The method is based on partitioning PP into a number of faces of equal link distance from a point, called a link-based shortest path map (SPM). Initially, we solve this problem for two given points ss, tt and a query point qq. Then, the proposed solution is extended to a general case for three arbitrary query points ss, tt and qq. In the former, we propose an algorithm with O(n)O(n) preprocessing time. Extending this approach for the latter case, we develop an algorithm with O(n3)O(n^3) preprocessing time. The link distance of a qq-visiblevisible path between ss, tt as well as the path are provided in time O(logn)O(\log n) and O(m+logn)O(m+\log n), respectively, for the above two cases, where mm is the number of links

    Complexity Growth Following Multiple Shocks

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    In this paper by making use of the "Complexity=Action" proposal, we study the complexity growth after shock waves in holographic field theories. We consider both double black hole-Vaidya and AdS-Vaidya with multiple shocks geometries. We find that the Lloyd's bound is respected during the thermalization process in each of these geometries and at the late time, the complexity growth saturates to the value which is proportional to the energy of the final state. We conclude that the saturation value of complexity growth rate is independent of the initial temperature and in the case of thermal initial state, the rate of complexity is always less than the value for the vacuum initial state such that considering multiple shocks it gets more smaller. Our results indicate that by increasing the temperature of the initial state, the corresponding rate of complexity growth starts far from final saturation rate value.Comment: 19 pages, 3 figs, Ref.s adde
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