Noncommutative Geometry, Algebraic and Differential Topology, Functional Analysis, $K$-theory of $C^*$-algebras, index theory of elliptic operators, Noncommutative Harmonic Analysis, Group Theory.
Main publications:
Troitsky E., “Geometric essence of “compact” operators on Hilbert C*-modules”, Journal of Mathematical Analysis and Applications, 485 (2020), 123842
Felshtyn A., Troitsky E., “Twisted Burnside-Frobenius theory for discrete groups”, J. Reine Angew. Math. (Crelle's journal), 613 (2007), 193–210
Pavlov A.A., Troitsky E.V., “A $C^*$-analogue of Kazhdan's property (T)”, Adv. in Math., 216 (2007), 75–88