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Showing posts from December 27, 2018

Metric for 2D de Sitter?

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3 3 What is the correct metric to use for two dimensional de Sitter? If one starts with the following metric, which looks similar to de Sitter in 4 dimensions: $$ds^2 = -dt^2 + e^{2H t} dx^2,$$ one can calculate $R = 2H^2$ , and $R_{00} = -H^2$ , which gives the $Lambda = 0$ , which is not the solution one is looking for. What should be the correct metric to use for the same? general-relativity differential-geometry metric-tensor de-sitter-spacetime share | cite | improve this question edited Dec 10 at 5:46 Qmechanic ♦ 101k 12 183 1145

Java: How can I effectively collect the data that three search algorithms return after breaking a lock?

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0 I have implemented three search algorithms (Breadth-First, Depth-Limited, and Iterative-Deepening Search) to collect data regarding time required and nodes visited to break a lock. A lock can have anywhere from a length one to a length 16 solution. To break a long, there are four actions available: poke, pull, twist, and shake. These algorithms utilize nodes which have a number corresponding to an action (the check function at the bottom of Tree class checks if a sequence of these actions represent the solution to break the lock) and they also have a reference to a parent. For each parent, there are 4 children, representative of the 4 available actions. Each algorithm traverses the nodes in their unique ways to arrive at a solution. The data that I would like to collect is the stack/queue size at the time of the solu