State of the art approaches for Information retrieval tasks based on deep learning
Deep learning extends the ability of information retrieval (IR) systems.

Deep learning has proved to be a powerful tool for feature engineering. This improvement in feature engineering, over manual construction, has improved the quality of any machine learning system, including information retrieval.

Specifically, word embeddings create a dense, vectorized representation of words that encodes the semantic relationships based on co-occurrence. Both documents and queries can be projected into the same latent space and nearest-neighbors can be found. Word embeddings can be used to extend the posting index to by finding related terms. They can also be used for query-expansion / query rewriting.