相关论文: Melonic Radiative Correction in Four-Dimensional S…
We revisit a model of the two-scalar system proposed previously for understanding a small but nonzero cosmological constant. The model provides solutions of the scalar-fields energy $\rho_s$ which behaves truly constant for a limited time…
The relativistic effects in cosmological observables contain critical information about the initial conditions and gravity on large scales. Compared to the matter density fluctuation, some of these relativistic contributions scale with…
We find the inconsistency of dimensional reduction and naive dimensional regularization in their applications to Chern-Simons type gauge theories. Further we adopt a consistent dimensional regularization to investigate the quantum…
In light of the most recent cosmological observations, we provide new updated constraints on the slow-roll inflation in different extended scenarios beyond the $\Lambda\rm{CDM}$ cosmological model. Along with the usual six parameters, we…
The solution of the null non-radial geodesic in a Schwarzschild-de Sitter background is revisited. The gravitational bending of a light ray is affected by the cosmological constant, in agreement with the findings of some previous…
As a test of the standard inflationary cosmology, which generically predicts nearly scale-invariant spectrum of primordial curvature fluctuations, we perform Markov-Chain Monte-Carlo analysis to search for possible modulations in the power…
There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…
Maxwell equations and the equations of General Relativity are scale invariant in empty space. The presence of charge or currents in electromagnetism or the presence of matter in cosmology are preventing scale invariance. The question arises…
We present and test a method that dramatically reduces variance arising from the sparse sampling of wavemodes in cosmological simulations. The method uses two simulations which are fixed (the initial Fourier mode amplitudes are fixed to the…
Cosmic microwave background (CMB) experiments that constrain the tensor-to-scalar ratio $r$ are now approaching the sensitivity at which delensing---removing the $B$ modes induced by the gravitational lensing of large-scale structure---is…
We study the cosmological consequences of a recently proposed nonlocal modification of general relativity, obtained by adding a term $m^2R\,\Box^{-2}R$ to the Einstein-Hilbert action. The model has the same number of parameters as…
This paper provides a mathematical approach to study chromatic aberration in metalenses. It is shown that radiation of a given wavelength is refracted according to a generalized Snell's law which together with the notion of envelope yields…
Cosmological observables in perturbation theory turn out to be plagued with infrared divergences, which represents both a conceptual and computational challenge. In this paper we present a proof of concept for a systematic procedure to…
Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on…
Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives…
Warped compactification of the six-dimensional bulk with a negative cosmological constant is realized with a 4-brane along with an abelian gauge theory. No fine tuning of couplings are needed to obtain the vanishing cosmological constant in…
We present a new limit on the cosmological constant based on the absence of correlations between the cosmic microwave background (CMB) and the distribution of distant radio sources. In the cosmological constant-cold dark matter models…
Cosmic rays (CRs) are an integral part of the non-thermal pressure budget in the interstellar medium (ISM) and are the leading-order ionization mechanism in cold molecular clouds. We study the impacts that different microphysical CR…
The cosmological reionization can be studied in the radio through the tomographic view offered by the redshifted 21-cm line and the integrated information carried out by the diffuse free-free emission, coupled to the Comptonization…
We point out several subtleties arising in brane-world scenarios of cosmological constant cancellation. We show that solutions with curvature singularities are inconsistent, unless the contribution to the effective four-dimentional…