125 citations · 1.1k across the 32 of their papers we have counts for
24 papers · 1 filter
To USR or not to USR: An effective description of two-field dynamics
Samuel Sánchez López, Eemeli Tomberg
Single-field models of inflection point inflation experience a phase of ultra-slow roll (USR), leading to amplified curvature perturbations. Recently, Lorenzoni et al. modified the…
Compaction function in stochastic inflation: a \texttt{FOREST} of type I and II primordial black holes
Chiara Animali, Pierre Auclair, Baptiste Blachier +2
We show how to compute the compaction function within stochastic inflation, by solving the random field dynamics on stochastic binary trees. In this framework, the compaction funct…
Effect of stochastic kicks on primordial black hole abundance and mass via the compaction function
Sami Raatikainen, Syksy Rasanen, Eemeli Tomberg
We study stochastic effects in viable ultra-slow-roll inflation models that produce primordial black holes. We consider asteroid, solar, and supermassive black hole seed masses. In…
Eternal inflation near inflection points: a challenge to primordial black hole models
Eemeli Tomberg, Konstantinos Dimopoulos
Inflation with an inflection point potential is a popular model for producing primordial black holes. The potential near the inflection point is approximately flat, with a local ma…
How deep is the dip and how tall are the wiggles in inflationary power spectra?
Vadim Briaud, Alexandros Karam, Niko Koivunen +3
We study linear scalar perturbations in single-field models of inflation featuring a non-attractor phase. These models lead to a peak in the curvature power spectrum that may resul…
Itô, Stratonovich, and zoom-in schemes in stochastic inflation
Eemeli Tomberg
The Itô and Stratonovich approaches are two ways to integrate stochastic differential equations. Detailed knowledge of the origin of the stochastic noise is needed to determine whi…
Stochastic Axion-like Curvaton: Non-Gaussianity and Primordial Black Holes Without Large Power Spectrum
Chao Chen, Anish Ghoshal, Gianmassimo Tasinato +1
We discuss a mechanism of primordial black hole (PBH) formation that does not require specific features in the inflationary potential, revisiting previous literature. In this mecha…
Primordial black hole numbers: standard formulas and charts
Eemeli Tomberg
This brief note presents standard computations of primordial black hole mass given perturbations of scale , and their late-time abundance given their initial…
Primordial black hole compaction function from stochastic fluctuations in ultra-slow-roll inflation
Sami Raatikainen, Syksy Rasanen, Eemeli Tomberg
We study the formation of primordial black holes (PBH) with ultra-slow-roll inflation when stochastic effects are important. We use the formalism and simplify the stochastic e…
Stochastic constant-roll inflation and primordial black holes
Eemeli Tomberg
Stochastic inflation resolves primordial perturbations non-linearly, probing their probability distribution deep into its non-Gaussian tail. The strongest perturbations collapse in…
Numerical stochastic inflation constrained by frozen noise
Eemeli Tomberg
Stochastic inflation can resolve strong inflationary perturbations, which seed primordial black holes. I present a fast and accurate way to compute these perturbations in typical b…
Anatomy of single-field inflationary models for primordial black holes
Alexandros Karam, Niko Koivunen, Eemeli Tomberg +2
We construct an analytically solvable simplified model that captures the essential features for primordial black hole (PBH) production in most models of single-field inflation. The…
The Linear Regime of Tachyonic Preheating
Niko Koivunen, Eemeli Tomberg, Hardi Veermäe
Tachyonic preheating is realized when the inflaton repeatedly returns to a convex region of the potential during the post-inflationary oscillating phase. This will induce a strong…
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…
A numerical approach to stochastic inflation and primordial black holes
Eemeli Tomberg
Certain models of cosmic inflation produce strong cosmological perturbations at short length scales, which may later collapse into primordial black holes. To find the statistics of…
Unit conversions and collected numbers in cosmology
Eemeli Tomberg
This note collects together useful unit conversions and numerical values from early universe cosmology. It is a quick reference that can be used to make easy order-of-magnitude est…
Tachyonic Preheating in Plateau Inflation
Eemeli Tomberg, Hardi Veermäe
Plateau inflation is an experimentally consistent framework in which the scale of inflation can be kept relatively low. Close to the edge of the plateau, scalar perturbations are s…
Tachyonic Preheating in Palatini Inflation
Alexandros Karam, Eemeli Tomberg, Hardi Veermäe
We study preheating in the Palatini formalism with a quadratic inflaton potential and an added term. In such models, the oscillating inflaton field repeatedly returns to the…
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{…
Critical point Higgs inflation in the Palatini formulation
Vera-Maria Enckell, Sami Nurmi, Syksy Rasanen +1
We study Higgs inflation in the Palatini formulation with the renormalisation group improved potential in the case when loop corrections generate a feature similar to an inflection…
Gravitational dark matter production in Palatini preheating
Alexandros Karam, Martti Raidal, Eemeli Tomberg
We study preheating in plateau inflation in the Palatini formulation of general relativity, in a special case that resembles Higgs inflation. It was previously shown that the oscil…
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…
Planck scale black hole dark matter from Higgs inflation
Syksy Rasanen, Eemeli Tomberg
We study the production of primordial black hole (PBH) dark matter in the case when the Standard Model Higgs coupled non-minimally to gravity is the inflaton. PBHs can be produced…
Higgs inflation at the hilltop
Vera-Maria Enckell, Kari Enqvist, Syksy Rasanen +1
We study inflation with the non-minimally coupled Standard Model Higgs in the case when quantum corrections generate a hilltop in the potential. We consider both the metric and the…