Welcome to Solitons at Work, an open and informal network of mathematics and physics researchers who work on solitons. Please have a look around the website.

Upcoming Seminars

12th November 2025 - 10am GMT

Étienne Fodor- Defect motility in pulsating active matter

When heartbeats become irregular due to tachycardia or fibrillation, spiral waves and motile defects emerge at the surface of cardiac tissues [1]. Capturing the emergence of such defects in confluent tissues without any cellular flow is a theoretical challenge which has recently been tackled by models of actively deforming particles [2-5]. In dense assemblies where particles are subject to individual pulsation of their sizes, the interplay between synchronization and repulsion can produce deformation waves resembling those observed in cardiac tissues. Combining particle-based and hydrodynamic approaches, we examine the statistics of defects in the collective deformation of particles. We rationalize the emergence of defect motility as stemming from the breakdown of time-reversal and spatial symmetries. Specifically, we provide analytical predictions for the deformation profile near the defect core to quantify the angular and translational velocities of defects. These results lead to identifying the dominant mechanism underlying the crossover between various deformation patterns in contractile tissues, with broader implications for understanding similar phenomena in other active systems.
[1] A. Karma, Annu. Rev. Condens. Matter Phys., 4, 313-337 (2013)
[2] Y. Zhang, É. Fodor, Phys. Rev. Lett., 131, 238302 (2023)
[3] A. Manacorda, É. Fodor, Phys. Rev. E, 111, L053401 (2025)
[4] W. Piñeros, É. Fodor, Phys. Rev. Lett., 134, 038301 (2025)
[5] T. Banerjee, et al., arXiv:2407.19955 (2024); arXiv:2509.19024 (2025)

26th November 2025 - 10am GMT

Corentin Coulais - Non-reciprocal Solitons

Controlling how waves propagate, attenuate and amplify in simple, scalable geometric structures is a daunting challenge for science and technology. In this talk, I will discuss how non-reciprocity can be used to steer mechanical waves in unprecedented ways. Combining experiments on active mechanical metamaterials with wave physics and continuum and topological mechanics, I will discuss the emergence of the non-Hermitian skin effect, of non-Hermitian topological waves and of unidirectional solitons. I will further show how these odd waves can be used to induce locomotion and unusual responses to impacts and hence pave the way towards a novel generation of robots.

Upcoming Coffee Clubs

14th November 2025, 10am GMT

News

Postdoc position in Soliton Physics at Henan University (Deadline: 1st December, 2025)

For more details, see S@W Jobs.