Metaplectic Demazure operators and Whittaker functions Gautam ChintaPaul GunnellsAnna Puskas Indiana University Mathematics Journal 2017 text pdf 10.1512/iumj.2017.66.6068 10.1512/iumj.2017.66.6068 en Indiana Univ. Math. J. 66 (2017) 1045 - 1064 state-of-the-art mathematics http://iumj.org/access/