• Mixed-integer (nonlinear) programming
• Machine learning
• Power Systems Modelling and Optimization
• Generalized Nash Games

Publications in journals:

• C. Neumann, O. Stein, Feasible rounding approaches for equality constrained mixed-integer optimization problems, Optimization, 2021, DOI: 10.1080/02331934.2021.1981894.
• C. Neumann, O. Stein, Generating feasible points for mixed-integer convex optimization problems by inner parallel, SIAM Journal on Optimization, Vol. 31 (2021), 2396-2428.
• L. Lampariello, C. Neumann, J.M. Ricci, S. Sagratella, O. Stein, Equilibrium selection for multi-portfolio optimization, European Journal of Operational Research (2021), DOI: 10.1016/j.ejor.2021.02.033.
• L. Lampariello, C. Neumann, J.M. Ricci, S. Sagratella, O. Stein, An explicit Tikhonov algorithm for nested variational inequalities , Computational Optimization and Applications, Vol. 77 (2020), 335-350.
• C. Neumann, O. Stein, N. Sudermann-Merx, Bounds on the objective value of feasible roundings, Vietnam Journal of Mathematics, Vol. 48 (2020), 299-313.
• C. Neumann, O. Stein, N. Sudermann-Merx, Granularity in nonlinear mixed-integer optimization, Journal of Optimization Theory and Applications, 2019, DOI 10.1007/s10957-019-01591-y.
• C. Neumann, O. Stein, N. Sudermann-Merx, A feasible rounding approach for mixed-integer optimization problems , Computational Optimization and Applications, 2018, DOI 10.1007/s10589-018-0042-y.
   

Submitted for Publication:

• C. Neumann, S. Schwarze, O. Stein, B. Müller, Feasible rounding approaches and diving strategies in branch-and-bound methods for mixed-integer optimization, Optimization Online, Preprint-ID 2021-10-8630, 2021.