相关论文: Lensing impact on cosmic relics and tensions
Using a sample of 608 Type Ia supernovae from the SDSS-II and BOSS surveys, combined with a sample of foreground galaxies from SDSS-II, we estimate the weak lensing convergence for each supernova line-of-sight. We find that the correlation…
In this thesis, I describe a number of recent important developments in neutrino cosmology on three fronts. Firstly, focusing on Large-Scale Structure (LSS) data, I will show that current cosmological probes contain a wealth of information…
We derive constraints on the relic abundance of a generic particle of mass $\sim~1-10^{14}$ TeV which decays into neutrinos at cosmological epochs, using data from the Fr\'ejus and IMB nucleon decay detectors and the Fly's Eye air shower…
We place bounds on long-lived primordial relics using measurements of the diffuse gamma ray spectrum from EGRET and COMPTEL. Bounds are derived for both radiative and hadronic decays with stronger bounds applying for the latter decay mode.…
The connection between cosmological observations and neutrino physics is discussed in detail. Neutrinos decouple from thermal contact in the early Universe at a temperature of order 1 MeV which coincides with the temperature where light…
Considering the mass splitting between three active neutrinos, we represent the new constraints on the sum of neutrino mass $\sum m_\nu$ by updating the anisotropic analysis of Baryon Acoustic Oscillation (BAO) scale in the CMASS and LOWZ…
For a wide variety of cosmological models characterized by the cosmic mass density $\Omega_M$ and the normalized cosmological constant $\Omega_{\Lambda}$, we derive an analytic expression for the estimate of magnification cross-sections by…
Measurements of time delays between multiple quasar images produced by strong lensing are reaching a sensitivity that makes them a promising cosmological probe. Future surveys will provide significantly more measurements, reaching…
The expansion history and thermal physical process that happened in the early Universe before big bang nucleosynthesis (BBN) remains relatively unconstrained by observations. Low reheating temperature universes with normalcy temperatures of…
We present strong bounds on the sum of three active neutrino masses ($\sum m_{\nu}$) in various cosmological models. We use the following baseline datasets: CMB temperature data from Planck 2015, BAO measurements from SDSS-III BOSS DR12,…
We present high signal-to-noise galaxy-galaxy lensing measurements of the BOSS CMASS sample using 250 square degrees of weak lensing data from CFHTLenS and CS82. We compare this signal with predictions from mock catalogs trained to match…
Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to…
We forecast constraints on the amplitude of matter clustering sigma_8(z) achievable with the combination of cluster weak lensing and number counts, in current and next-generation weak lensing surveys. We advocate an approach, analogous to…
After a short introduction on the predicted cosmic neutrino background in the universe, we review some of the cosmological bounds related to neutrinos. In particular we show how the recent data on the anisotropies of the cosmic microwave…
Cosmic microwave background polarization encodes information not only on the early universe but also dark energy, neutrino mass, and gravity in the late universe through CMB lensing. Ground based surveys such as ACTpol, PolarBear, SPTpol…
In recent years, a crisis in the standard cosmology has been caused by inconsistencies in the measurements of some key cosmological parameters, Hubble constant $H_0$ and cosmic curvature parameter $\Omega_K$ for example. It is necessary to…
We use new cosmic microwave background (CMB) primary temperature and polarization anisotropy measurements from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) to test foundational assumptions of the standard cosmological model…
We present new constraints on the rest-frame sound speed, c_{eff}^2, and the viscosity parameter, c_{vis}^2, of the Cosmic Neutrino Background from the recent measurements of the Cosmic Microwave Background anisotropies provided by the…
Strong gravitational lensing forms multiple, time delayed images of cosmological sources, with the "focal length" of the lens serving as a cosmological distance probe. Robust estimation of the time delay distance can tightly constrain the…
After reviewing the main mechanisms by which cosmological measurements constrain the sum of neutrino masses, I give the current reached upper limits, emphasizing the level of model-dependence. A large improvement is to be expected with…