Search results for "maailmankaikkeus"
showing 6 items of 6 documents
Euclid preparation XV. Forecasting cosmological constraints for the Euclid and CMB joint analysis
2022
The combination and cross-correlation of the upcoming $Euclid$ data with cosmic microwave background (CMB) measurements is a source of great expectation since it will provide the largest lever arm of epochs, ranging from recombination to structure formation across the entire past light cone. In this work, we present forecasts for the joint analysis of $Euclid$ and CMB data on the cosmological parameters of the standard cosmological model and some of its extensions. This work expands and complements the recently published forecasts based on $Euclid$-specific probes, namely galaxy clustering, weak lensing, and their cross-correlation. With some assumptions on the specifications of current and…
Dark energy, extended gravity, and solar system constraints
2008
Spherically symmetric inhomogeneous cosmological models
2014
Maailmankaikkeuden rakenne sekä tähdet ja planeetat Plinius vanhemman Naturalis historia -teoksen toisessa kirjassa
2003
Weakly interacting dark matter in walking technicolor theories
2010
Several lines of evidence support the existence of the dark matter in the Universe. In the light of the present observations the particle dark matter, and in particular the WIMP scenario is a very promising alternative to solve the dark matter problem. In this context recent minimal walking techicolor model motivated dark matter models have been studied. The minimal walking techinicolor and the minimal extension of it, which can successfully provide a dynamical origin for the electroweak symmetry breaking as well as the unification of the standard model coupling constants, gives rise to natural dark matter candidates such as fourth family heavy neutrinos and SU(2) adjoint matter. A general …
Black Hole Shadow Drift and Photon Ring Frequency Drift
2021
The apparent angular size of the shadow of a black hole in an expanding Universe is redshift-dependent. Since cosmological redshifts change with time - known as the redshift drift - all redshift-dependent quantities acquire a time-dependence, and a fortiori so do black hole shadows. We find a mathematical description of the black hole shadow drift and show that the amplitude of this effect is of order $10^{-16}$ per day for M87$^{\star}$. While this effect is small, we argue that its non-detection can be used to constrain the accretion rate around supermassive black holes, as well as a novel probe of the equivalence principle. If general relativity is assumed, we infer from the data obtaine…