{
  "id": "1912.07693",
  "version": "v1",
  "published": "2019-12-16T20:38:59.000Z",
  "updated": "2019-12-16T20:38:59.000Z",
  "title": "Gradient and GENERIC evolution towards reduced dynamics",
  "authors": [
    "Miroslav Grmela",
    "Vaclav Klika",
    "Michal Pavelka"
  ],
  "comment": "submitted",
  "categories": [
    "math-ph",
    "cond-mat.mes-hall",
    "math.MP",
    "physics.flu-dyn"
  ],
  "abstract": "Let (M,J) be a dynamical model of macroscopic systems and (N,K) a less microscopic model (i.e. a model involving less details) of the same macroscopic systems; M and N are manifolds, J are vector fields on M, and K are vector fields on N. Let P be the phase portrait corresponding to (M,J) (i.e. P is the set of all trajectories in M generated by a family of vector fields in J), and R the phase portrait corresponding to (N,K). Thermodynamics in its general sense is a pattern recognition process in which R is recognized as a pattern in P. In particular, the classical (both equilibrium and nonequilibrium) thermodynamics arises in the investigation of relations between models (M,J) and models without time evolution, i.e. models with K= 0. In such case R is a submanifold of M composed of fixed points. Let Su mapping M to R be a potential, called an upper entropy, generating the vector field J. The equilibrium thermodynamic relation in N is the lower entropy Sd(y) defined by Sd(y)=Su(x=y), where x is in M,y in N, and y is given by a final destination (i.e. when the time goes to infinity) of x in the time evolution generated by the vector field J. In this paper we show that if K is not zero (e.g. in externally forced or, in other words, open systems), then the reduction also provides thermodynamics (we call it flux-thermodynamics). If certain conditions are satisfied, then the lower entropy Ss, that arises in the investigation of the approach of J to K, is the time derivative of the lower entropy Sd arising in the investigation of the approach of M to N as t goes to infinity.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-12-16T20:38:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "vector field",
      "generic evolution",
      "reduced dynamics",
      "lower entropy sd",
      "phase portrait corresponding"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}