Rahil Valani

In a recent work, we show that a suspension of (non-interacting) deformable, elongated particles in oscillatory shear flow can develop nematic order via a phase synchronization mechanism. The work is published in @PhysRevLett : journals.aps.org/prl/abstract/1… @OxfordPhysics

Active Soft-Impact Oscillator: Dynamics of a Walking Droplet in a Non-Smooth Potential Titir Mukherjee, Rahil N Valani, Soumitro Banerjee arxiv.org/abs/2602.05913 [𝚗𝚕𝚒𝚗.𝙲𝙳 𝚙𝚑𝚢𝚜𝚒𝚌𝚜.𝚏𝚕𝚞-𝚍𝚢𝚗]

Wave-mediated interactions can drive rich collective dynamics in active particle clusters. We study walking droplet clusters that form stable bound states with collective excitation modes and show similarities with nuclear physics. Paper: doi.org/10.1103/4cgg-h…

In a joint work led by Brendan Harding, and with Yvonne Stokes, we develop a unified Hamiltonian framework for how active particles move in channel flows. Particles undergo complex trajectories but remain confined within predictable regions. @PhysRevE doi.org/10.1103/m9ks-m…

Quincke rotation, a particle spinning in an electric field, exhibits complex dynamics and follows the Lorenz equations. In a recent work, we show that fluid memory reshapes this chaos and delays its onset. @AdityaSKhair1 @PhysRevFluids journals.aps.org/prfluids/abstr…

More on collective behavior: Our new Annual Review of Biophysics piece - with the stellar Danielle Chase - explores how animals sense, share information, and make group decisions. In honeybees and beyond 🐝 annualreviews.org/content/journa…

New preprint - We show a Hamiltonian formulation for the motion of a simple active particle interacting with unidirectional steady flow. This provides insights into organization of the active particle trajectories as defined by a potential well. arxiv.org/abs/2506.11388

Postdoctoral position open in Bacterial-Algal Symbiosis! This interdisciplinary role will involve experimental and theoretical research using microfluidics, microscopy and modelling. Applications close May 13 (Aust. time). Please RT! @SciMelb @UniMelb jobs.unimelb.edu.au/caw/en/job/920…

An active particle inspired from walking droplets can unpredictably cross a potential barrier. Using a minimal model, we show that the unpredictability lies in non-equilibrium features of a perturbed Lorenz system @PhysRevE journals.aps.org/pre/abstract/1…

Attending the @APSphysics Global Physics Summit in Anaheim #APSSummit25. If you would like to learn about our recent work on active particles/mechanobiology, or just want to say hi, then I am presenting at the below sessions: summit.aps.org/events/MAR-T59… summit.aps.org/events/MAR-M00…

Using a simple model of a walking droplet in a harmonic potential, we show countably infinite quantized orbits, as opposed to a continous spectrum that one gets for a classical simple harmonic oscillator. See our open access paper below @PhysRevE : journals.aps.org/pre/abstract/1…

@ZacconeAlessio @PhysRevE Thanks for sharing, this looks very interesting! I will have a proper read of your paper.

@RahilValani @PhysRevE Very nice work. We recently found giant mobility due to memory accumulation in a system of passive charged particles in a driven bath, now in press @PhysRevE: arxiv.org/abs/2402.08519

Thanks @PhysRevE for highlighting our work :)

Adding a small bias force to a Lorenz model for a memory-driven active particle leads to both giant negative and positive mobility simultaneously, suggesting a mechanism by which anomalous transport emerges. Read the paper: go.aps.org/3Of6yt3

@indraghosh314 @PhysRevE Thanks :)

@RahilValani @PhysRevE This is very cool! Congrats Rahil.

Our below work in now published in @PhysRevE! We show that asymmetric limit cycles within Lorenz chaos can induce motion for an active particle in a direction opposite to an applied force. #chaos #activematter #walkingdroplet doi.org/10.1103/PhysRe…

Congratulations to Xinyi for the fist paper from her PhD. This work, together with @PrakashLab, is published in @RSocPublishing today, and examines individual and collective behaviour of magnetotactic bacteria in an oxygen gradient. @SciMelb @MelbMathBio royalsocietypublishing.org/doi/10.1098/rs…

#ICYMI: In wave-particle duality, electrons can become trapped in disordered environments. Now, researchers show that a similar effect can be seen in droplets on a vibrating fluid surface – results that could inform research on #ActiveMatter systems. 🔗 go.aps.org/3zwaFNB

We are advertising a postdoc position at @UniofAdelaide to work on mathematical modelling of inertial microfluidic technologies. If this sounds interesting please see below link or if you know anyone who might be interested please help spread the word