228 citations · 808 across the 15 of their papers we have counts for
15 papers
Inflation with the Gauss-Bonnet term in the Palatini formulation
Ali Hassan, Syksy Rasanen
We consider the Gauss-Bonnet term coupled to the inflaton in the Palatini formulation of gravity. Unlike in the metric formulation, the Gauss-Bonnet term is not always a total deri…
Inflation with the Chern-Simons term in the Palatini formulation
Ali Hassan, Syksy Rasanen
We consider the Chern--Simons term coupled to the inflaton in the Palatini formulation of general relativity. In contrast to the metric formulation, here the Chern--Simons term aff…
Scalar fields with derivative coupling to curvature in the Palatini and the metric formulation
Hamed Bouzari Nezhad, Syksy Rasanen
We study models where a scalar field has derivative and non-derivative couplings to the Ricci tensor and the co-Ricci tensor with a view to inflation. We consider both the metric f…
Stability of non-degenerate Ricci-type Palatini theories
Jaakko Annala, Syksy Rasanen
We study the stability of theories where the gravitational action has arbitrary algebraic dependence on the three first traces of the Riemann tensor: the Ricci tensor, the co-Ricci…
Palatini formulation for gauge theory: implications for slow-roll inflation
Syksy Rasanen, Yosef Verbin
We consider a formulation of gauge field theory where the gauge field and the field strength are independent variables, as in the Palatini formulation of gravity. Fo…
Implications of stochastic effects for primordial black hole production in ultra-slow-roll inflation
Daniel G. Figueroa, Sami Raatikainen, Syksy Rasanen +1
We study the impact of stochastic noise on the generation of primordial black hole (PBH) seeds in ultra-slow-roll (USR) inflation with numerical simulations. We consider the non-li…
The effect of dark matter discreteness on light propagation
Sofie Marie Koksbang, Syksy Rasanen
Light propagation in cosmology is usually studied in the geometrical optics approximation which requires the spacetime curvature to be much smaller than the light wavenumber. Howev…
Non-Gaussian tail of the curvature perturbation in stochastic ultra-slow-roll inflation: implications for primordial black hole production
Daniel G. Figueroa, Sami Raatikainen, Syksy Rasanen +1
We consider quantum diffusion in ultra-slow-roll (USR) inflation. Using the formalism, we present the first stochastic calculation of the probability distribution $P(\mathcal{…
Higgs inflation with the Holst and the Nieh-Yan term
Miklos Långvik, Juha-Matti Ojanperä, Sami Raatikainen +1
The action of loop quantum gravity includes the Holst term and/or the Nieh-Yan term in addition to the Ricci scalar. These terms are expected to couple non-minimally to the Higgs.…
Higgs inflation in the Palatini formulation with kinetic terms for the metric
Syksy Rasanen
We consider scalar field inflation in the Palatini formulation of general relativity. The covariant derivative of the metric is then non-zero. From the effective theory point of vi…
Narrowing the window of inflationary magnetogenesis
Tommi Markkanen, Sami Nurmi, Syksy Rasanen +1
We consider inflationary magnetogenesis where the conformal symmetry is broken by the term . We assume that the magnetic field power spectrum today between 0.…
Testing distance duality with CMB anisotropies
Syksy Rasanen, Jussi Valiviita, Ville Kosonen
We constrain deviations of the form from the standard redshift-temperature relation, corresponding to modifying distance duality as .…
CMB seen through random Swiss Cheese
Mikko Lavinto, Syksy Rasanen
We consider a Swiss Cheese model with a random arrangement of Lemaître--Tolman--Bondi holes in CDM cheese. We study two kinds of holes with radius Mpc, with eithe…
New test of the FLRW metric using the distance sum rule
Syksy Rasanen, Krzysztof Bolejko, Alexis Finoguenov
We present a new test of the validity of the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, based on comparing the distance from redshift 0 to and from to to…
Backreaction in late-time cosmology
Thomas Buchert, Syksy Rasanen
We review the effect of the formation of nonlinear structures on the expansion rate, spatial curvature and light propagation in the universe, focusing on the possibility that it co…