Quantum groups with partial commutation relations Roland SpeicherMoritz Weber Indiana University Mathematics Journal 2019 text pdf 10.1512/iumj.2019.68.7791 10.1512/iumj.2019.68.7791 en Indiana Univ. Math. J. 68 (2019) 1849 - 1883 state-of-the-art mathematics http://iumj.org/access/