{ "id": "2201.07176", "version": "v2", "published": "2022-01-18T18:22:15.000Z", "updated": "2022-02-07T16:02:11.000Z", "title": "Almost Complex Structures on Homotopy Complex Projective Spaces", "authors": [ "Keith Mills" ], "comment": "17 pages. Replaces an earlier version with very minor changes concerning the classification of homotopy complex projective spaces", "categories": [ "math.GT", "math.AT" ], "abstract": "We completely answer the question of when a homotopy $\\mathbb{C}P^n$, a smooth closed manifold with the oriented homotopy type of $\\mathbb{C}P^n$, admits an almost complex structure for $3 \\leq n \\leq 6$. For $3 \\leq n \\leq 5$ all homotopy $\\mathbb{C}P^n$s admit almost complex structures, while for $n=6$ there exist homotopy $\\mathbb{C}P^n$s that do not. Our methods provide a new proof of a result of Libgober and Wood on the classification of almost complex structures on homotopy $\\mathbb{C}P^4$s.", "revisions": [ { "version": "v2", "updated": "2022-02-07T16:02:11.000Z" } ], "analyses": { "subjects": [ "57R15", "57R20", "32Q60", "19L64" ], "keywords": [ "homotopy complex projective spaces", "complex structure", "smooth closed manifold", "oriented homotopy type", "classification" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }