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Ankur Gupta is the coauthor named with Roberto Grossi and Jeffrey Scott Vitter on their 2003 entropy-compressed text-index paper. Its wavelet tree represents a sequence through alphabet partitions and bitvectors. Navigating a symbol uses rank queries to map positions between successive partitions, supporting operations on a compressed index. This contribution concerns searchable sequence representations; it does not identify this author with unrelated people sharing the same name.^[ref]

By Roberto Grossi, Ankur Gupta, Jeffrey Scott Vitter.

Primary source: pages.di.unipi.it/grossi/PAPERS/sodaconf03FINAL-LATEST.pdf

Section 4.2, wavelet-tree relative-position encoding and Lemma 4.2.

Jeffrey Scott Vitter coauthored the 2003 work on entropy-compressed text indexes with Roberto Grossi and Ankur Gupta. It develops compressed suffix-array representations and introduces a wavelet tree representation for symbol sequences. Bitvectors route a position through alphabet partitions, with rank queries translating that position into the selected subsequence. This connects compressed storage to efficient indexing rather than requiring full decompression for every query.^[ref]

Roberto Grossi coauthored the 2003 entropy-compressed text-index paper with Ankur Gupta and Jeffrey Scott Vitter. The paper combines compressed suffix-array techniques with a wavelet tree, routing sequence positions through bitvectors that partition the alphabet. Its indexing bounds relate stored space to empirical entropy while retaining pattern-search functionality. The mathematical aim is both compression and access, rather than simply making a file small.^[ref]