Related papers: Non-linear Matter Spectrum for a Variable Equation…
If the dark energy equation of state is anisotropic, the expansion rate of the universe becomes direction-dependent at late times. We show that such models are not only cosmologically viable but that they could explain some of the observed…
Low energy interactions between particles are often characterised by elastic scattering. Just as electrons undergo Thomson scattering with photons, dark matter particles may experience an analogous form of momentum exchange with dark…
We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed linear theory power, increasing w leads to…
We investigate the nonlinear power spectra of density perturbations and acoustic oscillations in growing neutrino quintessence. In this scenario, the neutrino mass has a strong dependence on the quintessence field. The induced coupling…
Non-relativistic quantum effects of the topology of the spacetime with the distortion of a vertical line into a vertical spiral on the harmonic oscillator are investigated. By searching for analytical solutions to the Schr\"odinger equation…
We develop a new approach to study the nonlinear evolution in the large-scale structure of the Universe both in real space and in redshift space, extending the standard perturbation theory of gravitational instability. Infinite series of…
We analyze the dark matter power spectrum at three-loop order in standard perturbation theory of large scale structure. We observe that at late times the loop expansion does not converge even for large scales (small momenta) well within the…
The scale of Baryon Acoustic Oscillations (BAO) imprinted in the matter power spectrum provides an almost-perfect standard ruler: it only suffers sub-percent deviations from fixed comoving length due to non-linear effects. We study the BAO…
Late-time cosmic acceleration is one of the most interesting unsolved puzzles in modern cosmology. The explanation most accepted nowadays, dark energy, raises questions about its own nature, e.g. what exactly is dark energy, and…
We use a series of cosmological N-body simulations and various analytic models to study the evolution of the matter power spectrum in real space in a \Lambda Cold Dark Matter universe. We compare the results of N-body simulations against…
We investigate the third-order density perturbation and the one-loop correction to the linear power spectrum in the dark-energy cosmological model. Our main interest is to understand the dark-energy effect on baryon acoustic oscillations in…
We modify the public PM code developed by Anatoly Klypin and Jon Holtzman to simulate cosmology with arbitrary initial power spectrum and equation of state of dark energy. With this tool in hand, we perform the following studies on the…
We study the nonlinear evolution of density perturbations in cosmologies where the late-time accelerated expansion is driven by a quintessence field with vanishing speed of sound. For these models matter and quintessence perturbations are…
The galaxy power spectrum is now a well-known tool of precision cosmology. In addition to the overall shape, baryon oscillations and the small-scale suppression of power by massive neutrinos capture complimentary information on cosmological…
The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include…
We investigate the nonlinear evolution of structure in variants of the standard cosmological model which display damped density fluctuations relative to cold dark matter (e.g. in which cold dark matter is replaced by warm or interacting…
Nonlinear effects are crucial in order to compute the cosmological matter power spectrum to the accuracy required by future generation surveys. Here, a new approach is presented, in which the power spectrum, the bispectrum and higher order…
We reported results of our study on non-linear spherical perturbations in quintessence models of dark energy. In the process of some follow up studies we discovered that a scaling factor in the code used for numerical calculations that…
The quasi-static solutions of the matter density perturbation in various dark energy models and modified gravity models have been investigated in numerous papers. However, the oscillating solutions in those models have not been investigated…
In this work we discuss observational aspects of three time-dependent parameterisations of the dark energy equation of state $w(z)$. In order to determine the dynamics associated with these models, we calculate their background evolution…