You are provided with the abstract of a scientific paper and the abstracts of the papers it references. Your task is to write a Related Work section for the main paper. This section should concisely summarize and integrate the key points from the cited abstracts, reflecting how they relate to the main paper's contributions and context. In your summary, use numerical citation markers like [1], [2], etc., to refer to the corresponding papers.

Main Abstract:
Let @math @math be a given set of @math string documents of total length @math , our task is to index @math , such that the @math most relevant documents for an online query pattern @math of length @math can be retrieved efficiently. We propose an index of size @math bits and @math query time for the basic relevance metric , where @math is the size (in bits) of a compressed full text index of @math , with @math time for searching a pattern of length @math . We further reduce the space to @math bits, however the query time will be @math , where @math is the alphabet size and @math is any constant.

Cited Abstract(s):
[1]: Self-indexes are able to represent a text asymptotically within the information-theoretic lower bound under the kth order entropy model and offer access to any text substring and indexed pattern searches. Their time complexities are not optimal, however; in particular, they are always multiplied by a factor that depends on the alphabet size. In this article, we achieve, for the first time, full alphabet independence in the time complexities of self-indexes while retaining space optimality. We also obtain some relevant byproducts.
Table gives a summary of the major results in the top- @math frequent document retrieval problem. The time complexities are simplified by assuming that we are using the full text index proposed by Belazzougui and Navarro, of size @math bits and @math , where @math is the @math th order empirical entropy of @math [1] . We also assume @math for some @math and @math is any constant.