We here propose a new class of barotropic factor for matter , motivated by properties of isotropic deformations of crystalline solids .
Our approach is dubbed Anton-Schmidt ’ s equation of state and provides a non-vanishing , albeit small , pressure term for matter .
The corresponding pressure is thus proportional to the logarithm of universe ’ s volume , i.e .
to the density itself since V \propto \rho ^ { -1 } .
In the context of solid state physics , we demonstrate that by only invoking standard matter with such a property , we are able to frame the universe speed up in a suitable way , without invoking a dark energy term by hand .
Our model extends a recent class of dark energy paradigms named logotropic dark fluids and depends upon two free parameters , namely n and B .
Within the Debye approximation , we find that n and B are related to the Grüneisen parameter and the bulk modulus of crystals .
We thus show the main differences between our model and the logotropic scenario , and we highlight the most relevant properties of our new equation of state on the background cosmology .
Discussions on both kinematics and dynamics of our new model have been presented .
We demonstrate that the \Lambda CDM model is inside our approach , as limiting case .
Comparisons with CPL parametrization have been also reported in the text .
Finally , a Monte Carlo analysis on the most recent low-redshift cosmological data allowed us to place constraints on n and B .
In particular , we found n = -0.147 ^ { +0.113 } _ { -0.107 } and B = 3.54 \times 10 ^ { -3 } .