The zig-zag product
نویسنده
چکیده
The expander constructions based on algebraic methods can give expanders that are both explicit (i.e. we can quickly construct the graph, or even obtain neighborhood information without constructing the entire graph, and Ramanujan, meaning that the spectral gap is essentially as large as possible. It also follows from this spectral bound that the edge expansion of Ramanujan graphs is essentially as large as possible. So why do we need some other expander construction? One reason is the consideration of vertex expansion. Define
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تاریخ انتشار 2010