51 citations · 239 across the 17 of their papers we have counts for
17 papers
Enhanced Gravitational Effects of Radiation and Cosmological Implications
Hemza Azri, Kemal Gültekin, Adrian K. E. Tee
In the momentarily comoving frame of a cosmological fluid, the determinant of the energy-momentum tensor (EMT) is highly sensitive to its pressure. This component is significant du…
Gravity from the Determinant of the Energy-Momentum: Astrophysical Implications
Hemza Azri, Salah Nasri
Determinants of the second-rank tensors stand useful in forming generally invariant terms as in the case of the volume element of the gravitational actions. Here, we extend the act…
Isocurvature modes and non-Gaussianity in affine inflation
Hemza Azri, Isaac Bamwidhi, Salah Nasri
Inflationary dynamics driven by multiple fields, especially with nonminimal couplings, allow for highly interesting features such as isocurvature, non-Gaussianity, and preheating.…
Ricci-Determinant Gravity: Dynamical Aspects and Astrophysical Implications
Hemza Azri, K. Yavuz Ekşi, Canan Karahan +1
The Palatini gravitational action is enlarged by an arbitrary function of the determinants of the Ricci tensor and the metric, . The res…
Dynamical aspects of asymmetric Eddington gravity with scalar fields
Hemza Azri, Salah Nasri
In Eddington gravity, the action principle involves only the symmetric parts of the connection and the Ricci tensor, with a metric that emerges proportionally to the latter. Here,…
Scalar-Connection Gravity and Spontaneous Scalarization
Hemza Azri, Salah Nasri
Scalar-tensor theories of gravity are known to allow significant deviations from general relativity through various astrophysical phenomena. In this paper, we formulate a scalar-co…
Affine gravitational scenario for dark matter decay
Hemza Azri, Adil Jueid, Canan Karahan +1
Since the current evidence of its existence is revealed only through its gravitational influence, the way dark matter couples to gravity must be then of primary importance. Here, u…
Entropy Production in Affine Inflation
Hemza Azri, Salah Nasri
Multiple scalar fields nonminimally interacting through pure affine gravity are considered to generate primordial perturbations during an inflationary phase. The couplings consider…
Inducing Gravity From Connections and Scalar Fields
Hemza Azri
We propose an approach to induced gravity, or Sakharov's "metrical elasticity", which requires only an affine spacetime that accommodates scalar fields. The setup provides the indu…
Cosmological Implications of Affine Gravity
Hemza Azri
The main aim of this thesis is to reveal some interesting aspects of the purely affine theory of gravity and its cosmological implication. A particular attention will be devoted to…
Induced Affine Inflation
Hemza Azri, Durmus Demir
Induced gravity, metrical gravity in which gravitational constant arises from vacuum expectation value of a heavy scalar, is known to suffer from Jordan frame vs. Einstein frame am…
Are there really conformal frames? Uniqueness of affine inflation
Hemza Azri
Here we concisely review the nonminimal coupling dynamics of a single scalar field in the context of purely affine gravity and extend the study to multifield dynamics. The coupling…
Affine Inflation
Hemza Azri, Durmus Demir
Affine gravity, a gravity theory based on affine connection with no notion of metric, supports scalar field dynamics only if scalar fields have non-vanishing potential. The non-van…
Separate Einstein-Eddington Spaces and the Cosmological Constant
Hemza Azri
Based on Eddington affine variational principle on a locally product manifold, we derive the separate Einstein space described by its Ricci tensor. The derived field equations spli…
Eddington's Gravity in Immersed Spacetime
Hemza Azri
We formulate Eddington's affine gravity in a spacetime which is immersed in a larger eight dimensional space endowed with a hypercomplex structure. The dynamical equation of the fi…
Cosmological Consequences of a Variable Cosmological Constant Model
Hemza Azri, A. Bounames
We derive a model of dark energy which evolves with time via the scale factor. The equation of state is studied as a function of a parameter introduced in thi…
Geometrical Origin of the Cosmological Constant
Hemza Azri, A. Bounames
We show that the description of the space-time of general relativity as a diagonal four dimensional submanifold immersed in an eight dimensional hypercomplex manifold, in torsionle…