121 citations · 407 across the 26 of their papers we have counts for
26 papers
Is our vacuum global in a 331 model with three triplets?
Kristjan Kannike, Niko Koivunen, Aleksei Kubarski
We consider a 331 model, based on , with three triplets with a softly broken symmetry. The resulting scalar potential is commonly used in phen…
Dark matter in the scale-invariant 3-3-1-1 model
Alex G. Dias, Kristjan Kannike, Niko Koivunen +3
We propose a novel scale-invariant model with the 3-3-1-1 gauge symmetry featuring a universal see-saw mechanism for all fermion masses, which, through the inclusion of additional…
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…
On the family discrimination in 331-model
Katri Huitu, Niko Koivunen, Timo Kärkkäinen +1
In the so-called 331-models the gauge anomalies cancel only if there are three generations of fermions. This requires one of the quark generations to be in a different representati…
Probing sterile neutrino freeze-in at stronger coupling
Niko Koivunen, Oleg Lebedev, Martti Raidal
The regime of dark matter (DM) freeze-in at stronger coupling interpolates between freeze-in and freeze-out. It relies on Boltzmann-suppressed dark matter production, implying that…
Production and decays of 146 GeV flavons into final state at the LHC
Niko Koivunen, Martti Raidal
The CMS experiment at CERN has reported a possible signal for a resonance at 146 GeV decaying into the final state which, presently, is the only experimental hint for lepton f…
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…
Dark Matter-Induced Multi-Phase Dynamical Symmetry Breaking
Kristjan Kannike, Niko Koivunen, Aleksei Kubarski +4
We consider the classically scale invariant Higgs-dilaton model of dynamical symmetry breaking extended with an extra scalar field that plays the role of dark matter. The Higgs bos…
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…
Multi-phase critical Higgs boson at colliders
Katri Huitu, Kristjan Kannike, Niko Koivunen +3
The recently proposed multi-phase criticality principle in Coleman-Weinberg models can provide a new explanation for the hierarchy between the electroweak and new physics scales. W…
New fermions in the light of the
J. C. Criado, A. Djouadi, N. Koivunen +3
The very precise measurement of the anomalous magnetic moment of the muon, recently released by the Muon g-2 experiment at Fermilab, can serve to set stringent constraints on new p…
An effective field theory of the Delta-resonance
Juan Carlos Criado, Abdelhak Djouadi, Niko Koivunen +3
We present an effective field theory of the -resonance as an interacting Weinberg's field in the multi-spinor formalism. We derive its interactions with…
Confronting spin-3/2 and other new fermions with the muon g-2 measurement
Juan C. Criado, Abdelhak Djouadi, Niko Koivunen +3
The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using a…
Higher-spin particles at high-energy colliders
Juan Carlos Criado, Abdelhak Djouadi, Niko Koivunen +2
Using an effective field theory approach for higher-spin fields, we derive the interactions of colour singlet and electrically neutral particles with a spin higher than unity, conc…
Principle of Multiple Point Criticality in Multi-Scalar Dark Matter Models
Kristjan Kannike, Niko Koivunen, Martti Raidal
The principle of multiple point criticality (PMPC), which allowed the prediction of the Higgs boson mass before its discovery, has so far been applied to radiatively generated vacu…
Dark matter of any spin -- an effective field theory and applications
Juan Carlos Criado, Niko Koivunen, Martti Raidal +1
We develop an effective field theory of a generic massive particle of any spin and, as an example, apply this to study higher-spin dark matter (DM). Our formalism does not introduc…
Pseudo-Goldstone dark matter: gravitational waves and direct-detection blind spots
Tommi Alanne, Nico Benincasa, Matti Heikinheimo +4
Pseudo-Goldstone dark matter is a thermal relic with momentum-suppressed direct-detection cross section. We study the most general model of pseudo-Goldstone dark matter arising fro…
Natural neutrino sector in a 331-model with Froggatt-Nielsen mechanism
Katri Huitu, Niko Koivunen, Timo J. Kärkkäinen
The extensions of the Standard Model based on the gauge group (331-models) have been advocated to explain the number of fermion families in nat…
Suppression of scalar mediated FCNCs in a -model
Katri Huitu, Niko Koivunen
The models based on gauge symmetry (331-models) have been advocated to explain the number of fermion families. These models place one quark fam…
Neutrino mass via linear seesaw, 331-model and Froggatt-Nielsen mechanism
Katri Huitu, Niko Koivunen, Timo J. Kärkkäinen
In this paper, we introduce an extension of the Standard Model, based on SU(3)SU(3)U(1) gauge symmetry (331-model). The 331-models tradi…
Direct and indirect probes of Goldstone dark matter
Tommi Alanne, Matti Heikinheimo, Venus Keus +2
There exists a general model framework where dark matter can be a vanilla WIMP-like thermal relic with a mass of (100 GeV), but it still escapes direct detection. This ha…
Cosmological constraints on light flavons
Matti Heikinheimo, Katri Huitu, Venus Keus +1
The Froggatt-Nielsen mechanism is a well-motivated framework for generating the fermion mass hierarchy. This mechanism introduces flavons, complex scalars which are singlet under t…
Probing pseudo-Goldstone dark matter at the LHC
Katri Huitu, Niko Koivunen, Oleg Lebedev +2
Pseudo-Goldstone dark matter coupled to the Standard Model via the Higgs portal offers an attractive framework for phenomenologically viable pseudo-scalar dark matter. It enjoys na…
Singlet scalar and 2HDM extensions of the Standard Model: CP-violation and constraints from and EDM
Venus Keus, Niko Koivunen, Kimmo Tuominen
We study popular scalar extensions of the Standard Model, namely the singlet extension, the 2-Higgs doublet model (2HDM) and its extension by a singlet scalar. We focus on the cont…