532 citations · 3k across the 37 of their papers we have counts for
37 papers
Spectator dark matter in non-standard cosmologies
Catarina Cosme, Tommi Tenkanen
It has been shown that the observed dark matter (DM) abundance can be produced by amplification of quantum fluctuations of an energetically subdominant scalar field during inflatio…
The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
Rouzbeh Allahverdi, Mustafa A. Amin, Asher Berlin +23
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. W…
Gravitational wave constraints on the observable inflation
Erwin H. Tanin, Tommi Tenkanen
Gravitational waves (GW) produced in the early Universe contribute to the number of relativistic degrees of freedom, , during Big Bang Nucleosynthesis (BBN). By using…
Violation of slow-roll in non-minimal inflation
Tomo Takahashi, Tommi Tenkanen, Shuichiro Yokoyama
We show that a non-minimal coupling to gravity can not only make some inflationary models consistent with cosmological data, similar to the case of Higgs inflation, but can also in…
Initial conditions for plateau inflation: a case study
Tommi Tenkanen, Eemeli Tomberg
We study initial conditions for inflation in scenarios where the inflaton potential has a plateau shape. Such models are those most favored by Planck data and can be obtained in a…
Tracing the high energy theory of gravity: an introduction to Palatini inflation
Tommi Tenkanen
We present an introduction to cosmic inflation in the context of Palatini gravity, which is an interesting alternative to the usual metric theory of gravity. In the latter case onl…
Trans-Planckian Censorship, Inflation and Dark Matter
Tommi Tenkanen
If the inflationary phase lasted longer than the minimal period, the length scales observed today originate from modes that were smaller than the Planck length during inflation. It…
Axion dark matter from Higgs inflation with an intermediate
Tommi Tenkanen, Luca Visinelli
In order to accommodate the QCD axion as the dark matter (DM) in a model in which the Peccei-Quinn (PQ) symmetry is broken before the end of inflation, a relatively low scale of in…
Standard model Higgs field and hidden sector cosmology
Tommi Tenkanen
We consider scenarios where the inflaton field decays dominantly to a hidden dark matter (DM) sector. By studying the typical behavior of the Standard Model (SM) Higgs field during…
Dark matter from scalar field fluctuations
Tommi Tenkanen
Dark matter (DM) may have its origin in a pre-Big Bang epoch, the cosmic inflation. Here, we consider for the first time a broad class of scenarios where a massive free scalar fiel…
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…
Spectator Dark Matter
Tommi Markkanen, Arttu Rajantie, Tommi Tenkanen
The observed dark matter abundance in the Universe can be fully accounted for by a minimally coupled spectator scalar field that was light during inflation and has sufficiently str…
Minimal Higgs inflation with an term in Palatini gravity
Tommi Tenkanen
It has recently been suggested that the Standard Model Higgs boson could act as the inflaton while minimally coupled to gravity - given that the gravity sector is extended with an…
Towards distinguishing variants of non-minimal inflation
Tomo Takahashi, Tommi Tenkanen
We study models of inflation where the scalar field that drives inflation is coupled non-minimally to gravity via , or where the gravity sector is enlarged by an …
Hidden Inflaton Dark Matter
Juan P. Beltrán Almeida, Nicolás Bernal, Javier Rubio +1
If cosmic inflation was driven by an electrically neutral scalar field stable on cosmological time scales, the field necessarily constitutes all or part of dark matter (DM). We stu…
Scalar singlet dark matter in non-standard cosmologies
Nicolás Bernal, Catarina Cosme, Tommi Tenkanen +1
We study production of dark matter (DM) in models with a non-standard expansion history. We consider both freeze-out and freeze-in mechanisms for producing the observed DM abundanc…
Attractor Behaviour in Multifield Inflation
Pedro Carrilho, David Mulryne, John Ronayne +1
We study multifield inflation in scenarios where the fields are coupled non-minimally to gravity via , where are coupling constants, the fields…
Primordial Black Hole Formation During Slow Reheating After Inflation
Bernard Carr, Konstantinos Dimopoulos, Charlotte Owen +1
We study the formation of primordial black holes (PBHs) in the early Universe during a period of slow reheating after inflation. We demonstrate how the PBH formation mechanism may…
Phenomenology of Self-Interacting Dark Matter in a Matter-Dominated Universe
Nicolás Bernal, Catarina Cosme, Tommi Tenkanen
We study production of self-interacting dark matter (DM) during an early matter-dominated phase. As a benchmark scenario, we consider a model where the DM consists of singlet scala…
Prospects for indirect detection of frozen-in dark matter
Matti Heikinheimo, Tommi Tenkanen, Kimmo Tuominen
We study observational consequences arising from dark matter (DM) of non-thermal origin, produced by dark freeze-out from a hidden sector heat bath. We assume this heat bath was po…
The Palatini side of inflationary attractors
Laur Järv, Antonio Racioppi, Tommi Tenkanen
We perform an analysis of models of chaotic inflation where the inflaton field is coupled non-minimally to gravity via . We focus on the Palatini the…
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…
A novel way to determine the scale of inflation
Kari Enqvist, Robert J. Hardwick, Tommi Tenkanen +2
We show that in the Feebly Interacting Massive Particle (FIMP) model of Dark Matter (DM), one may express the inflationary energy scale as a function of three otherwise unrel…
Resurrecting Quadratic Inflation with a non-minimal coupling to gravity
Tommi Tenkanen
We study Quadratic Inflation with the inflaton field coupled non-minimally to the curvature scalar , so that the potential during inflation is of the form $V\propto m^2ϕ^2+ξ…