We show that the Suslov nonholonomic rigid body problem studied in [10, 13, 26] can be regarded almost everywhere as a generalized Chaplygin system. Furthermore, this provides a new example of a multidimensional nonholonomic system which can be reduced to a Hamiltonian form by means of Chaplygin reducing multiplier. Since we deal with Chaplygin systems in the local sense, the invariant manifold...

We want to study the perturbation growth of an initial seed of an ellipsoidal shape in Top-Hat collapse model of the structure formation in the Modied Chaplygin gas cosmology. Considering reasonable values of the constants and the parameters of the model under study, we can show that a very small deviation from spherical symmetry (ellipsoidal geometry) in the initial seed leads to a nal highly ...

We explicitly demonstrate that, contrary to recent claims, the dynamics of a generalized Chaplygin gas model with an equation of state p = −C (where C is a positive constant) is equivalent to that of a standard ΛCDM model to first order in the metric perturbations. We further argue that the analogy between the two models goes well beyond linear theory and conclude that they cannot be distinguis...

In this article, we present a fermionic extension of the scalar Born-Infeld equation, which has been derived from the Nambu-Goto superstring action in (2 + 1) dimensions through the Cartesian parameterization. It is demonstrated that in the relativistic limit where c → ∞, the fermionic Born-Infeld model reduces to the supersymmertic Chaplygin gas model in one spatial dimension. However, the sup...

The possibility that the present acceleration of the universe is driven by a kind of viscous fluid is exploited. At background level this model is similar to the generalized Chaplygin gas model (GCGM). But, at perturbative level, the viscous fluid exhibits interesting properties. In particular the oscillations in the power spectrum that plagues the GCGM are not present. Possible fundamental des...

In this article, we present a fermionic extension of the scalar Born-Infeld equation, which has been derived from the Nambu-Goto superstring action in (2 + 1) dimensions through the Cartesian parameterization. It is demonstrated that in the relativistic limit where c → ∞, the fermionic Born-Infeld model reduces to the supersymmetric Chaplygin gas model in one spatial dimension. However, the sup...