相关论文: Ballistic Dark Matter oscillates above $\Lambda$CD…

Current data in the form of baryon acoustic oscillation, supernova, and cosmic microwave background distances prefer a cosmology that accelerates more strongly than $\Lambda$CDM at $z\approx0.5-1.5$, and more weakly at $z\lesssim0.5$. We…

We consider a recently proposed model in which dark matter interacts with a thermal background of dark radiation. Dark radiation consists of relativistic degrees of freedom which allow larger values of the expansion rate of the universe…

The Lambda-Cold Dark Matter (LCDM) model agrees with most of the cosmological observations, but has some hindrances from observed data at smaller scales such as galaxies. Recently, Berezhiani and Khoury (2015) proposed a new theory…

We continue our work on a proposal for what dark matter could be, namely that the dark matter consists of essentially macroscopic objects built from ordinary matter. The only element of new physics is that there should exist several types…

We study a two-parameter extension of the cosmological standard model $\Lambda$CDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energy density in the dark radiation fluid…

We investigate an extension of $\Lambda$CDM in which a fraction of cold Dark Matter (DM) decays into invisible dark radiation (DR) around the radiation-matter equality epoch, together with a non-standard dark energy (DE) equation of state…

We investigate the effects of warm dark matter (WDM) on the cosmic 21-cm signal. If dark matter exists as WDM instead of cold dark matter (CDM), its non-negligible velocities can inhibit the formation of low-mass halos that normally form…

We suggest that an interplay between microscopic and macroscopic physics can give rise to dark matter (DM) whose interactions with the visible sector fundamentally undulate in time, independent of celestial dynamics. A concrete example is…

Despite their tremendous successes, modern-day cosmology and particle physics harbor a variety of unresolved mysteries. Two of the biggest are the origin of the baryon asymmetry of the Universe and the existence and nature of dark matter.…

Creation of Cold Dark Matter (CCDM) can macroscopically be described by a negative pressure, and, therefore, the mechanism is capable to accelerate the Universe, without the need of an additional dark energy component. In this framework we…

General relativity can be reconciled with quantum field theory without quantising the geometry only if the metric evolves stochastically. In this article, we explore the consequences of such a proposal at early cosmological times. We find…

We propose that dark matter (DM) possesses a quadratic equation of state, which becomes significant at high densities, altering the Universe's evolution during its early stages. We derive the modified background evolution equations for the…

First-order phase transitions (FOPT) are ubiquitous in beyond the Standard Model physics and leave distinctive echoes in the history of early universe. We consider a FOPT serving the well-motivated role of dark matter mass generation and…

Through analytic techniques verified by numerical calculations, we establish general relations between the matter and cosmic microwave background (CMB) power spectra and their dependence on cosmological parameters on small scales.…

We examine the cosmic microwave background power spectrum for adiabatic models with a massive neutrino component. We present the results of a detailed numerical evolution of cold + hot dark matter (CHDM) models and compare with the standard…

The existence of a landscape of metastable vacua raises the possibility that our Universe may have undergone quantum vacuum decay at late times. This work explores how such a transition can be tested with cosmological observables, focusing…

In two recent papers (arXiv:1106.4546, arXiv:1107.0721), we introduced "dynamical dark matter" (DDM), a new framework for dark-matter physics in which the requirement of stability is replaced by a delicate balancing between lifetimes and…

Dark matter-baryon interactions can cool the baryonic fluid, which has been shown to modify the cosmological 21-cm global signal. We show that in a two-component dark sector with an interacting millicharged component, dark matter-baryon…

Isocurvature fluctuations can be generated in various scenarios in the early Universe. In particular, some specific models predict those with a blue-tilted spectrum, which is consistent with the constraints from cosmic microwave background…

Potential small-scale discrepancies in the picture of galaxy formation painted by the $\Lambda$CDM paradigm have led to considerations of modified dark matter models. One such dark matter model that has recently attracted much attention is…