Dynamical Systems Lab (DSL), led by Prof. Piyush Grover in Mechanical and Materials Engineering (MME) at University of Nebraska-Lincoln, focusses on modeling and analysis of nonlinear dynamical systems with an eye on design, control and optimization for engineering applications. Our current focus is on active fluids, mean-field control, mean-field games and nonlinear waves in mechanical metamaterials.
Dec 2025: A preprint "Symmetry, Invariant Manifolds and Flow Reversals in Active Nematic Turbulence" led by graduate student Angel Naranjo provides the first deterministic characterization of active turbulence, using the exact coherent structure framework.
Paper Link: https://arxiv.org/abs/2512.07047
Checkout the associated videos: Youtube playlist
- Nov 2025: Angel Naranjo presented a talk titled "Symmetry, Invariant Manifolds and Flow Reversals in Active Nematic Channel flow" at APS DFD 2025.
- Oct 2025: Mohammed A. Mohammed presented a talk titled "Solitary wave - Breather Collisions in a Flexible Metamaterial Lattice: Dynamical Transitions Mediated by High-dimensional Saddle Points" at the Society of Engineering Science (SES) Annual Technical Meeting 2025.
- Mar 2025: Checkout our recent work on an application of tube dynamics and invariant manifold theory to mean field games "Topological bifurcations in a mean-field game" published in Proc. Royal Society A,. led by Ph.D. student Ali Rezaei Lori.
- Dec 2024: See our latest paper "Phase transition in a kinetic mean-field game model of inertial self-propelled agents" now published in Chaos
- Nov 2024: See our work on chemomechanical systems "Mechanochemical Topological Defects in an Active Nematic" now published in Physical Review E
- March 2024: DSL group presented 3 papers at APS March Meeting 2024
- Nov 2023: "Exploring regular and turbulent flow states in active nematic channel flow via Exact Coherent Structures and their invariant manifolds" is published in Physical Review Fluids
- July 2023: UNL News article about our DEPSCoR award.
- May 2023: Two talks at SIAM Conference on Dynamical Systems by graduate students Ali and Mohammed.
- May 2023: A new award from DoD will support our research on defect engineering of nonlinear wave propagation in bistable metamaterials
- May 2023: New preprint "Exploring regular and turbulent flow states in active nematic channel flow via Exact Coherent Structures and their invariant manifolds" led by Caleb Wagner.
- March 2023: Three talks at APS March meeting, by Ph.D. students Mohammed A. Mohammed, and Rumayel Pallock, as well as our collaborator Dr. Mike Norton of RIT.
- Oct 2022: New preprint "Mechanochemical topological defects in an active nematic" with Mike Norton.
- July 2022: New preprint "Phase space analysis of nonlinear wave propagation in a bistable mechanical metamaterial with a defect", led by Ph.D. student Mohammed A. Mohammed. See our USNC/TAM presentation here. Update: Now published in Physical Review E, here
- June 2022: Two presentations at USNC/TAM 2022 in Austin. One talk on ECS in active nematics, and another on nonlinear wave propagation in bistable metamaterials.
- April 2022: Presentation at UNL Math Club
- April 2022: MME Graduate seminar presentation titled "From celestial mechanics to active hydrodynamics: hitchhiking on invariant manifolds through chaos in finite and infinite dimensions"
- March 2022: New Article "Robust preconditioned one-shot methods and direct-adjoint-looping for optimising Reynolds-averaged turbulent flows" in Computers and Fluids.
- Feb 2022: Caleb Wagner presented in UC Merced's SLAAM seminar. Watch the recording here.
- Jan 2022: DSL work highlighted in PRL as Editor's Suggestion
- Dec 2021: New Article "Co-design of reduced-order models and observers from thermo-fluid data" in IFAC Journal of Systems and Control.
- Nov 2021: See our research covered by UNL Engineering : From bacteria to robot swarms to mixed traffic: Researchers developing new algorithms for controlling collective behavior
- Nov 2021: Upcoming talk at APS DFD 2021 by Caleb Wagner, and video @ APS Gallery of Fluids.
- Oct 2021 : Upcoming Brandeis MRSEC Seminar, as well as Brandeis Physics Colloqium.
- Sept 2021 : New DOE Basic Energy Science award will support our research on nonlinear dynamics and control of active fluids using exact coherent structures framework.
- Sept 2021 : New preprint: Exact coherent structures and phase space geometry of pre-turbulent 2D active nematic channel flow. See videos here. Published in Physical Review Letters
- July 2021 : New NSF CMMI DCSD award will support our research on bifurcations and phase space analysis of Mean field games and mean field control problems
- July 2021: Invited talk at Active matter workshop @ Telluride Science Research Center, Colorado.
- July 2021: Ph.D. Position: We are looking for a Ph.D. student in the area of active fluids. Please email me with any inquiries.
- June 2021: Upcoming talks at: Midwest Thermodynamics and Statistical Mechanics Workshop, and ICRA workshop on nano and micro-robots.
- May 2021: 3 Talks at SIAM Dynamical Systems Conference: On Mean field games, Exact coherent structures in active nematics, and control of active nematics
- March 2021: Caleb presented work on Exact Coherent Structures in active nematics at APS
- Oct 2020: Our paper Optimal Control of Active Nematics is highlighted in Physical Review Letters as Editor's Suggestion.
- Sept 2020: Paper with colleagues from Georgia Tech, accepted at Conference on Decision and Control (CDC 2020) 'Stabilizing Optimal Density Control of Nonlinear Agents with Multiplicative Noise'. Preprint coming soon.
- August 2020: Caleb Wagner will join the group as a postdoctoral researcher, after finishing his Ph.D. in non-equilibrium statistical mechanics at Brandeis University.
- July 2020: Check out our new preprint "Optimal Control of Active Nematics" with Mike Norton and collaborators. Accepted at Physical Review Letters (9/18)
- May 2020: New undergraduate online course "Nonlinear Dynamics and Chaos' will be offered during 8 week summer session (MECH 98-401, May 18-July 10). Sign up now to learn about this exciting topic.
- April 2020: Our paper 'Optimization-based incentivization and control scheme for autonomous traffic' with Uros Kalabic (MERL) and Shuchin Aeron (Tufts) on PDE based optimal control of mixed manual-autonomous traffic accepted to IEEE Intelligent Vehicles 2020. Preprint here
- Feb 2020: Joint work with Mike Norton on optimal control of active nematics will be presented by Mike at the APS March Meeting.
- Jan 2020: Paper accepted at American Control Conference (ACC 2020) with colleagues from MERL and Univ. Minnesota on robust estimation of airflow in buildings. Preprint forthcoming.
- Nov 2019: Conference APS Division of Fluid Dynamics Meeting Nov 2019: 2 Talks with collaborators from MERL and Univ. Cambridge.
- Nov 2019: Presented work on mean-field games at UNL Math Department's Continuum Mechanics Seminar
- Oct 2019: New poster on LiDAR based data assimilimation.
- Oct 2019: A new postdoctoral position is available. See ad here.
- Sept 2019: New paper with colleagues from MERL and Univ. Cambridge on optimal control of airflow in buildings.
- August 2019: DSL is established. We are looking for undergraduate and graduate students to join the lab.
- July 2019: Workshop Particulate and Granular Networks, Max Planck Institute for Physics of Complex Systems, Dresden, Germany
- June 2019:Workshop Crowds: Models and Control workshop, CIRM, Marseille, France
- May 2019: Conference SIAM Conference on Applications of Dynamical Systems, Snowbird, Utah. Presented a talk on MFG based flocking models and their stability analysis.
Areas of Research
Dynamical Systems theory, reduced-order modeling, control and optimization with applications to:
- Microfluidics and active fluids (chaotic mixing, topological chaos, flow control)
- Large-scale multi-agent systems (swarm robotics, traffic) via mean-field games and mean-field control theory
- Energy transfers and wave propagation in nonlinear metamaterials and achitectured materials
- Atmospheric Flows (Reduced-order modeling , LiDAR data-assimilation)
- Astrodynamics (Low-energy space mission design)
- Buoyancy driven flow in built environment (control of HVAC)
Funded by:
- NSF CMMI DCSD 2102112 (PI:Grover)
- DOE BES Biomolecular materials DE-SC0022280 (PI:Grover, Co-Is:Jae Sung Park, Michael M. Norton)
- DoD/AFOSR DEPSCoR (PI:Grover, co-PI: Keegan Moore (UNL))
- Mitsubishi Electric Research Labs
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