caa a22 4500 605525900 CHVBK 20210128100800.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s10958-015-2535-x doi (NATIONALLICENCE)springer-10.1007/s10958-015-2535-x Constructing the SU(2) × U(1) Orbit Space for Qutrit Mixed States [Elektronische Daten] [V. Gerdt, A. Khvedelidze, Y. Palii] The orbit space of the group G := SU(2) × U(1) ⊂ U(3) acting adjointly on the state space of a three-level quantum system is discussed. The semialgebraic structure of is determined within the Procesi-Schwarz method. Using an integrity basis for the ring of G-invariant polynomials , the set of constraints on the Casimir invariants of the group U(3) coming from the positivity requirement Grad(z) ≥ 0 for the Procesi-Schwarz gradient matrix is analyzed in detail. Springer Science+Business Media New York, 2015 Gerdt V. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna International University for Nature, Society, and Man, Dubna, Russia aut Khvedelidze A. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Russia aut Palii Y. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Russia aut Journal of Mathematical Sciences Springer US; http://www.springer-ny.com 209/6(2015-09-01), 878-889 1072-3374 209:6<878 2015 209 10958 https://doi.org/10.1007/s10958-015-2535-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10958-015-2535-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gerdt V. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna International University for Nature, Society, and Man, Dubna, Russia aut NATIONALLICENCE 700 1- Khvedelidze A. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Russia aut NATIONALLICENCE 700 1- Palii Y. Laboratory of Information Technologies, Joint Institute for Nuclear Research, Dubna, Russia aut NATIONALLICENCE 773 0- Journal of Mathematical Sciences Springer US; http://www.springer-ny.com 209/6(2015-09-01), 878-889 1072-3374 209:6<878 2015 209 10958