{ "id": "1703.10874", "version": "v1", "published": "2017-03-31T12:10:30.000Z", "updated": "2017-03-31T12:10:30.000Z", "title": "A recursive algorithm and a series expansion related to the homogeneous Boltzmann equation for hard potentials with angular cutoff", "authors": [ "Nicolas Fournier" ], "categories": [ "math.AP" ], "abstract": "We consider the spatially homogeneous Boltzmann equation for hard potentials with angular cutoff. This equation has a unique conservative weak solution $(f_t)_{t\\geq 0}$, once the initial condition $f_0$ with finite mass and energy is fixed. Taking advantage of the energy conservation, we propose a recursive algorithm that produces a $(0,\\infty)\\times\\mathbb{R}^3$ random variable $(M_t,V_t)$ such that $E[M_t {\\bf 1}_{\\{V_t \\in \\cdot\\}}]=f_t$. We also write down a series expansion of $f_t$. Although both the algorithm and the series expansion might be theoretically interesting in that they explicitly express $f_t$ in terms of $f_0$, we believe that the algorithm is not very efficient in practice and that the series expansion is rather intractable. This is a tedious extension to non-Maxwellian molecules of Wild's sum and of its interpretation by McKean.", "revisions": [ { "version": "v1", "updated": "2017-03-31T12:10:30.000Z" } ], "analyses": { "subjects": [ "82C40", "60K35" ], "keywords": [ "series expansion", "hard potentials", "angular cutoff", "recursive algorithm", "unique conservative weak solution" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }