Suppose that balls, where is a constant, are thrown sequentially to bins, all of which are initially empty. Let be the number of empty bins after we have thrown balls. Clearly, . Let’s see how we can understand this sequence of random variables. When we move from step to we throw a ball. It either falls in an […]
The sphericity of a graph is the smallest dimension such that there exists a mapping such that if and only if . The following theorem is due to Frankl and Maehara and is a nice application of random projections. Here, . Theorem [Frankl-Maehara 1988]: Let be a graph with minimum adjacency eigenvalue where and suppose . […]
This formula is well known and is given as an exercise for integration by parts. Here is a nice alternative proof I came across due to Inna Zakharevich. . Now differentiate times wrt to and set .
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