N.V.Brilliantov T.Poeschel W.T.Kranz A.Zippelius Translations and Rotations Are Correlated in Granular Gases 2007 In a granular gas of rough particles the axis of rotation is shown to be correlated with the translational velocity of the particles. The average relative orientation of angular and linear velocities depends on the restitution coefficients – the parameters which characterize the dissipative nature of the collision [1,2]. Using the Boltzmann equation and pseudo-Liouville operator technique [1,3] we derive a simple analytical theory for these correlations. We also perform numerical simulations for a wide range of coefficients of normal and tangential restitution. Two different numerical methods were used: Direct simulation Monte Carlo (DSMC) [4] and event-driven molecular dynamics (MD). Surprisingly, the limit of smooth spheres was found to be singular: even an arbitrarily small roughness of the particles gives rise to orientational correlations. The results of the analytical theory are in a good agreement with the numerical simulations [5]. 1) N.V. Brilliantov and T. Poeschel, Kinetic Theory of Granular Gases (Oxford University Press, Oxford, 2004).\ 2) T. Poeschel, and N.V. Brilliantov (Eds.), Granular Gas Dynamics, Lecture Notes in Physics, vol. 624, Springer (2003).\ 3) T. Aspelmeier, M. Huthmann, and A. Zippelius, in Granular Gases, S. Luding and T. Poeschel (Eds), Lecture Notes in Physics vol. 425, Springer, Berlin, (2000), p. 680.\ 4) T. Poeschel and T. Schwager, Computational Granular Dynamics (Springer, New York, 2005).\ 5) N.V. Brilliantov, T. Poeschel, W.T. Kranz, and A. Zippelius, Phys. Rev. Lett., 98, (2007) 128001. N.V.Brilliantov Yu.A.Andrienko P.L.Krapivsky Pattern formation in size-polydisperse adsorption: fractal properties and transition to order Physica A: Statistical and Theoretical Physics 239 267–275 1997 N.V.Brilliantov V.P.Denisov P.L.Krapivsky Generalized Stokes-Einstein-Debye relation for charged Brownian particles in solution Physica A: Statistical and Theoretical Physics 175 293–304 1991 N.V.Brilliantov D.V.Kuznetsov R.Klein Chain collapse and counterion condensation in dilute polyelectrolyte solutions Phys. Rev. Lett. 81 1433–1436 1998 A quantitative theory for polyelectrolytes in salt-free dilute solutions is developed. Depending on the electrostatic interaction strength, polyelectrolytes in solutions can undergo strong stretching (with polyelectrolyte dimension R-g similar to l(B)(1/3)N where l(B) is the Bjerrum length and N is the number of the chain segments) or compression (with R-g similar to l(B)(-1/2) N-1/3). A strong polymer collapse occurs as a first-order phase transition due to accompanying counterion condensation. NikolaiV.Brilliantov ThorstenPoschel Self-diffusion in granular gases: Green–Kubo versus Chapman–Enskog Chaos: An Interdisciplinary Journal of Nonlinear Science AIP 15 026108 2005 NikolaiV.Brilliantov FrankSpahn Dust coagulation in equilibrium molecular gas. Mathematics and Computers in Simulation 72 93-97 2006 NikolaiV.Brilliantov FrankSpahn Jan-MartinHertzsch ThorstenP\"oschel The collision of particles in granular systems Physica A: Statistical and Theoretical Physics 231 417–424 1996 FrankSpahn Jan-MartinHertzsch NikolaiV.Brilliantov The role of particle collisions for the dynamics in planetary rings Chaos, Solitons & Fractals 5 1945–1964 1995