192 citations · 1.3k across the 33 of their papers we have counts for
12 papers · 1 filter
Scalar correlation functions for a double-well potential in de Sitter space
Tommi Markkanen, Arttu Rajantie
We use the spectral representation of the stochastic Starobinsky-Yokoyama approach to compute correlation functions in de Sitter space for a scalar field with a symmetric or asymme…
Dark energy without fine tuning
José Eliel Camargo-Molina, Tommi Markkanen, Pat Scott
We present a two-field model that realises inflation and the observed density of dark energy today, whilst solving the fine-tuning problems inherent in quintessence models. One fie…
Scalar correlation functions in de Sitter space from the stochastic spectral expansion
Tommi Markkanen, Arttu Rajantie, Stephen Stopyra +1
We consider light scalar fields during inflation and show how the stochastic spectral expansion method can be used to calculate two-point correlation functions of an arbitrary loca…
Non-minimal gravitational reheating during kination
Konstantinos Dimopoulos, Tommi Markkanen
A new mechanism is presented which can reheat the Universe in non-oscillatory models of inflation, where the inflation period is followed by a period dominated by the kinetic densi…
Horizon Feedback Inflation
Malcolm Fairbairn, Tommi Markkanen, David Rodriguez-Roman
We consider the effect of the Gibbons-Hawking radiation on the inflaton in the situation where it is coupled to a large number of spectator fields. We argue that this will lead to…
Quantum corrections to quartic inflation with a non-minimal coupling: metric vs. Palatini
Tommi Markkanen, Tommi Tenkanen, Ville Vaskonen +1
We study models of quartic inflation where the inflaton field is coupled non-minimally to gravity, , and perform a study of quantum corrections in curved space-time at…
Light scalars on cosmological backgrounds
Tommi Markkanen
We study the behaviour of a light quartically self-interacting scalar field on curved backgrounds that may be described with the cosmological equation state parameter . At l…
De Sitter Stability and Coarse Graining
Tommi Markkanen
We present a 4-dimensional back reaction analysis of de Sitter space for a conformally coupled scalar field in the presence of vacuum energy initialized in the Bunch-Davies vacuum.…
Decoherence Can Relax Cosmic Acceleration: an Example
Tommi Markkanen
We investigate back reaction in de Sitter space in an approach where only states that are observationally accessible are included in the density matrix. Using the Bunch-Davies vacu…
Massive scalar field evolution in de Sitter
Tommi Markkanen, Arttu Rajantie
The behaviour of a massive, non-interacting and non-minimally coupled quantised scalar field in an expanding de Sitter background is investigated by solving the field evolution for…
Curvature induced running of the cosmological constant
Tommi Markkanen
In this work we investigate the renormalization group flow of the cosmological constant induced by the change in space-time curvature in the electroweak vacuum. We calculate th…
Quantum Corrections to Inflaton and Curvaton Dynamics
Tommi Markkanen, Anders Tranberg
We compute the fully renormalized one-loop effective action for two interacting and self-interacting scalar fields in FRW space-time. We then derive and solve the quantum corrected…