204 citations · 1.2k across the 40 of their papers we have counts for
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The Jordan algebras of Riemann, Weyl and curvature compatible tensors
Carlo Alberto Mantica, Luca Guido Molinari
Given the Riemann, or the Weyl, or a generalized curvature tensor K, a symmetric tensor is named `compatible' with the curvature tensor if $b_i{}^m K_{jklm} + b_j{}^m K_{k…
On the uniqueness of a shear-vorticity-acceleration-free velocity field in space-times
Luca Guido Molinari, Adriano Tacchini, Carlo Alberto Mantica
We prove that in space-times a velocity field that is shear, vorticity and acceleration-free, if any, is unique up to reflection, with these exceptions: generalized Robertson-Walke…
Cosmological perfect fluids in higher-order gravity
Salvatore Capozziello, Carlo Alberto Mantica, Luca Guido Molinari
We prove that in Robertson-Walker space-times (and in generalized Robertson-Walker spacetimes of dimension greater than 3 with divergence-free Weyl tensor) all higher-order gravita…
Cosmological perfect fluids in Gauss-Bonnet gravity
Salvatore Capozziello, Carlo Alberto Mantica, Luca Guido Molinari
In an -dimensional Friedmann-Robertson-Walker metric, it is rigorously shown that any analytical theory of gravity , where is the curvature scalar and $\cal G…
w=1/3 to w=-1 evolution in a Robertson-Walker space-time with constant scalar curvature
Luca Guido Molinari, Carlo Alberto Mantica
The Ricci tensor of a Robertson-Walker space-time is here specified by requiring constancy of the scalar curvature and a vanishing spatial curvature. By entering this Ricci tensor…
Gray s decomposition on doubly warped product manifolds and applications
Hoda K. El-Sayed, Carlo Alberto Mantica, Sameh Shenawy +1
A. Gray presented an interesting invariant decomposition of the covariant derivative of the Ricci tensor. Manifolds whose Ricci tensor satisfies the defining pr…
Perfect-fluid, generalised Robertson-Walker space-times, and Gray's decomposition
Carlo Alberto Mantica, Luca Guido Molinari, Young Jin Suh +1
We give new necessary and sufficient conditions on the Weyl tensor for generalized Robertson-Walker (GRW) space-times to be perfect-fluid space-times. For GRW space-times, we deter…