This work deals with F (T ) gravity models driven by real scalar fields with usual and phantom dynamics. We illustrate the results with examples of current interest, and we find some analytical solutions for scale factors and scalar fields. The results indicate that torsionscalar models also admit the accelerated expansion of the universe.

In this paper, we consider three types of k-essence. These k-essence models were presented in the parametric forms. The exact analytical solutions of the corresponding equations of motion are found. It is shown that these k-essence models for the presented solutions can give rise to cosmic acceleration.

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The present work addresses the study and characterization of the integrability of some generalized Heisenberg ferromagnet equations (GHFE) in 1+1 dimensions. Lax representations for these GHFE are successfully obtained. The gauge equivalent counterparts of these integrable GHFE are presented.

In this paper, we obtained a class of oscillatory, cyclic and knot type solutions from the non-linear Friedmann equations. This is performed by choosing specific forms of energy density and pressure of matter. All the expressions written here are in dimensionless form. We show that evolutionary path taken by the spatial coordinates in the model follow various knots, specifically trefoil and eight-knots. We provide several examples and plot relevant cosmological parameters in figures. Our cyclic models can be interpreted as a periodic cosmological model, such that early and late time acceleration are unified under the same mechanism. Finally we have presented some examples of knot universes for the Bianchi -I spacetime.