Zobrazeno 1 - 10
of 107
pro vyhledávání: '"Markkanen, Tommi"'
Based on the current experimental data, the Standard Model predicts that the current vacuum state of the Universe is metastable, leading to a non-zero rate of vacuum decay through nucleation of bubbles of true vacuum. Our existence implies that there
Externí odkaz:
http://arxiv.org/abs/2207.00696
Autor:
Karam, Alexandros, Markkanen, Tommi, Marzola, Luca, Nurmi, Sami, Raidal, Martti, Rajantie, Arttu
We show that the observed primordial perturbations can be entirely sourced by a light spectator scalar field with a quartic potential, akin to the Higgs boson, provided that the field is sufficiently displaced from vacuum during inflation. The framew
Externí odkaz:
http://arxiv.org/abs/2103.02569
We derive lower bounds for the Higgs-curvature coupling from vacuum stability during inflation in three inflationary models: quadratic and quartic chaotic inflation, and Starobinsky-like power-law inflation. In contrast to most previous studies we ta
Externí odkaz:
http://arxiv.org/abs/2011.03763
Autor:
Karam, Alexandros, Markkanen, Tommi, Marzola, Luca, Nurmi, Sami, Raidal, Martti, Rajantie, Arttu
We demonstrate that light spectator fields can source sizeable CMB anisotropies through modulated reheating even in the absence of direct couplings to the inflaton. The effect arises when the phase space of the inflaton decay is modulated by the spec
Externí odkaz:
http://arxiv.org/abs/2006.14404
Publikováno v:
JCAP 08 (2020) 002
We demonstrate that adiabatic dark matter can be generated by gravity induced symmetry breaking during inflation. We study a $Z_2$ symmetric scalar singlet that couples to other fields only through gravity and for which the symmetry is broken by the
Externí odkaz:
http://arxiv.org/abs/2005.04061
Autor:
Markkanen, Tommi, Rajantie, Arttu
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 asymmetric double-well potential. The terms in the spectral expansion are de
Externí odkaz:
http://arxiv.org/abs/2001.04494
Publikováno v:
JHEP 1901 (2019) 044
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 field acts as the inflaton, generically driving the other to a saddle-poi
Externí odkaz:
http://arxiv.org/abs/1905.00045
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 local function of the field in de Sitter space. In particular, we use this
Externí odkaz:
http://arxiv.org/abs/1904.11917
Publikováno v:
JCAP 1909 (2019) 023
We investigate compatibility between the stochastic infrared (IR) resummation of light test fields on inflationary spacetimes and renormalisation group running of the ultra-violet (UV) physics. Using the Wilsonian approach, we derive improved stochas
Externí odkaz:
http://arxiv.org/abs/1904.11373
We present a novel mechanism for the production of primordial black holes (PBHs). The mechanism is based on a period of thermal inflation followed by fast-roll inflation due to tachyonic mass of order the Hubble scale. Large perturbations are generat
Externí odkaz:
http://arxiv.org/abs/1903.09598