16. A computer-implemented retrieval method operating on a database of documents including text and names of participants associated with the documents, the retrieval method comprising: receiving a retrieval query having at least one of a text query facet comprising one or more keywords and a persons query facet comprising one or more participant names; performing query enrichment including at least one of: (1) computing an enriched text query as an aggregation of the text query facet, a monomodal expansion of the text query facet based on the one or more keywords, a cross-modal expansion of the text query facet based on the one or more participant names, and a topic expansion of the text query facet based on a topic model associating words and topics, and (2) computing an enriched persons query as an aggregation of the persons query facet, a monomodal expansion of the persons query facet based on the one or more participant names, a cross-modal expansion of the persons query facet based on the one or more keywords, and a community expansion of the persons query facet based on a community model associating persons and communities; and performing ranking including at least one of: (1) generating a ranking of documents by sorting similarities between the enriched text query and documents of the database, and (2) generating a ranking of persons by sorting the enriched persons query; wherein the retrieval method is performed by a computer; and wherein the cross-modal expansion of the text query facet is proportional to X w T X u u q where u q is a vector representing the persons query facet, X w is a term-document matrix associating words with documents of the database and X u is a participant-document matrix associating participants with documents of the database; and displaying the ranking of the documents or person query.
16. A computer-implemented retrieval method operating on a database of documents including text and names of participants associated with the documents, the retrieval method comprising: receiving a retrieval query having at least one of a text query facet comprising one or more keywords and a persons query facet comprising one or more participant names; performing query enrichment including at least one of: (1) computing an enriched text query as an aggregation of the text query facet, a monomodal expansion of the text query facet based on the one or more keywords, a cross-modal expansion of the text query facet based on the one or more participant names, and a topic expansion of the text query facet based on a topic model associating words and topics, and (2) computing an enriched persons query as an aggregation of the persons query facet, a monomodal expansion of the persons query facet based on the one or more participant names, a cross-modal expansion of the persons query facet based on the one or more keywords, and a community expansion of the persons query facet based on a community model associating persons and communities; and performing ranking including at least one of: (1) generating a ranking of documents by sorting similarities between the enriched text query and documents of the database, and (2) generating a ranking of persons by sorting the enriched persons query; wherein the retrieval method is performed by a computer; and wherein the cross-modal expansion of the text query facet is proportional to X w T X u u q where u q is a vector representing the persons query facet, X w is a term-document matrix associating words with documents of the database and X u is a participant-document matrix associating participants with documents of the database; and displaying the ranking of the documents or person query. 18. The retrieval method of claim 16 wherein: the retrieval query includes both a text query facet and a persons query facet, and the performing of query enrichment includes both computing an enriched text query and computing an enriched persons query.