We study the survival of giant clumps in high-redshift disc galaxies, short-lived (S) versus long-lived (L) and two L sub-types, via analytic modeling and simulations. We develop a criterion for clump survival, with/without gas, based on a survivability parameter S. It compares the energy sources by supernova feedback and gravitational contraction to the clump binding energy and losses by outflows and turbulence dissipation. The clump properties are derived from Toomre instability, approaching virial/Jeans equilibrium, and the supernova energy deposit uses an up-to-date bubble analysis. For moderate feedback, we find L clumps with circular velocities ∼50 km s−1 and masses ≥108M⊙. They favor galaxies with circular velocities ≥200 km s−1, consistent at z ∼ 2 with the typical disc stellar mass, ≥109.3M⊙. L clumps favor disc gas fractions ≥ 0.3, low-mass bulges and z∼2. They disfavor more effective feedback due to, e.g. supernova clustering, very strong radiative feedback, top-heavy stellar mass function, or particularly high star-formation-rate (SFR) efficiency. A sub-type of L clumps (LS), which lose their gas in several free-fall times but retain bound stellar components, may be explained by less contraction and stronger gravitational effects, where clump mergers increase the SFR efficiency. These may give rise to globular clusters. The more massive L clumps (LL) retain most of their baryons for tens of free-fall times with a roughly constant star-formation rate.

Soliton in multipulse laser waveforms interact by suppression of quasi-cw fluctuations. Experiments in graphene-based and nonlinear-multimode-interference-based fiber lasers and theoretical analysis demonstrate the interactions manifest with stagnation points, accelerating trajectories, collisions, soliton molecules and phase locking transitions.

We report a dynamical transition between steady states of optical solitons in a mode-locked fiber laser. We model the transition theoretically using a Haus equation-based numerical simulation and a simplified analytical model.

We the steady states of two-soliton waveforms that form stationary bound states in a fiber laser, passively mode-locked by a nonlinear-multimode-interference based saturable absorber. We model the steady states using noise-mediated Casimir-like pulse interaction mechanism.