Strange attractors induced by melting in systems with nonreciprocal effective interactions

Non-reciprocity induces resonances in a two-field Cahn–Hilliard model

“…Such an homogeneous behaviour is, however, incompatible with a fully conserved dynamics. 3 Instead, the stationary or oscillatory mode with the smallest wavenumber compatible with the boundary conditions is excited, e.g. for periodic boundary conditions its wavelength equals the domain size.…”

“…To our knowledge, such states have not yet been systematically studied in systems with conservation laws although some states of similar complexity are described for an active phase-field-crystal model for a mixture of active and passive particles [43]. The instability limits of both symmetric and asymmetric stationary solutions merge at the double zero singularity located at ϕ = 3 4 π , μ = 1 4 . Further details, involving elaborate calculations, are given in appendix Ac.…”

“…Breaking Newton's third law has recently become a cherished pastime for theoretical physicists and applied mathematicians alike [1][2][3][4][5]. This not only formally breaks the boring symmetry in particle-particle interactions, but has dire consequences for the system's behaviour: particles are not anymore attracted or repelled by their common centre of mass (that remains at rest) but instead may start a chasing race as one (the 'predator') is attracted by the other one, while the latter (the 'prey') is repelled by the first one [6].…”

Extracting Forces from Noisy Dynamics in Dusty Plasmas

“…The particles experience a wide array of forces including electrostatic repulsion, hydrodynamic drag from neutral and charged ions, and stochastic thermal kicks [12]. As a result, dusty plasmas display a wide range of complex, nonequilibrium dynamical phenomena, including superthermal excitations from non-reciprocal forces [13][14][15], oscillations between "turbulent" and "quiescent" states [16][17][18], parametric resonance and kinetic heating [19][20][21], spontaneous oscillations at low pressures [22,23], helical dust "strings" [24,25], and vortical structure formation at high magnetic fields [26][27][28]. However, the individual interactions between particles are a subject of active research [29][30][31][32], and the external forces acting on a single particle can be complex [22,[33][34][35].…”

“…The first is Eq. 6, and the second model is derived from a potential (mf w = −dφ w /dr) that incorporates the virtual charge from the ion wake beneath each particle [18]:…”