Kavli Affiliate: Anthony Lasenby | Summary:For electromagnetism in Minkowski spacetime, the Bessel-Hagen method gives a particularly direct Noetherian derivation of the standard gauge-invariant energy-momentum tensor. The key step is to supplement the form variation generated by an infinitesimal coordinate transformation with a compensating electromagnetic gauge transformation. In this paper we ask whether the same idea […]
Kavli Affiliate: Blake Sherwin | Summary:We present a new method for fast computation of the realization-dependent bias, a major computational bottleneck in measurements of the cosmic microwave background (CMB) lensing power spectrum. The method accelerates the bias calculation by differencing two correlated estimates: one based on fully realistic masked simulations and the other on isotropic […]
Kavli Affiliate: Kaisey Mandel | Summary:Astrophysical variabilities of Type Ia supernovae (SNe Ia), such as their link with their birth environment, are now one of the leading sources of systematic uncertainties on the measurement of the dark energy equation-of-state parameter $w$. Population studies of SNe Ia, using large samples, give precious insights into these variabilities. […]
Kavli Affiliate: Roberto Maiolino | Summary:We test whether “little red dots” (LRDs) are the dust-reddened, high-inclination counterparts of bluer compact broad-line active galactic nuclei, here referred to as “little blue dots” (LBDs), by modeling their relative number densities and luminosities. Using the observed UV luminosity function (LF) of broad-line active galactic nuclei (BLAGNs) at z>4 […]
Kavli Affiliate: Blake Sherwin | Summary:We present new constraints on the local-type primordial non-Gaussianity parameter, $f_mathrmNL^mathrmlocal$, through analysis of the scale-dependent bias effect on the cosmic infrared background (CIB). To avoid biases from galactic dust contamination on large scales, we use cross-correlations between the CIB and Planck cosmic microwave background (CMB) lensing maps to constrain […]
Kavli Affiliate: Roberto Maiolino | Summary:Recent JWST observations have revealed that some galaxies at $z gtrsim 7$ generally exhibit relatively flat ultraviolet (UV) attenuation curves and a weak UV bump. These features suggest that the first dust grains formed rapidly, possibly originating from core-collapse supernovae (SNe). We investigate the time evolution of grain size distributions […]
Kavli Affiliate: Ulrich Sperhake | Summary:We explore the gravitational-wave phenomenology of equal-mass inspiralling boson-star binaries using numerical relativity simulations. In particular, we characterise the waveform differences between binary boson-star and black-hole systems across (i) the early inspiral, by matching our waveforms to post-Newtonian expressions, (ii) merger, and (iii) late ringdown, by extracting the quasi-normal mode […]
Kavli Affiliate: Roberto Maiolino | Summary:JWST has revealed an overabundance of very bright, blue galaxies at z>10, raising fundamental questions about how star formation and feedback operate at Cosmic Dawn. We present new JWST/NIRSpec MSA PRISM/CLEAR spectroscopy of JADES-GS-z14-0 (z=14.18) obtained with the JADES and OASIS programmes. While the rest-frame UV continuum flux level and […]
Kavli Affiliate: George Efstathiou | Summary:High-mass X-ray binaries are one of the primary drivers of the 21-cm signal from Cosmic Dawn and Reionization, playing a leading role in the thermal history of the intergalactic medium. In traditional semi-numerical simulations, a deterministic scaling relation between the total X-ray luminosity of high-mass X-ray binaries, $L_rm X$, and […]
Kavli Affiliate: Roberto Maiolino | Summary:JWST has revealed a large population of massive black holes (BHs) in the early Universe with unusual properties which mark them as distinct from low-redshift active galactic nuclei. Such findings have prompted the development of new models of BH formation and growth, and of their co-evolution with host galaxies. Linking […]