A University of Illinois College of Law professor, who was investigated by the university last year following allegations of sexual misconduct, has agreed to take a one-year leave of absence.The latest development about professor Jay P. Kesan came in a letter on Thursday from law school dean Vikram D. Amar to members the law school community. Senior Associate Dean for Academic Affairs Eric A. Johnson and four members of the college of law’s executive committee also signed the letter.“Although the Office of the …