Kavli Affiliate: George Efstathiou | Summary:Several Decadal-level questions in astrophysics, exoplanets, astrobiology, and cosmology can be addressed only at low radio frequencies inaccessible from Earth. The MegaWave Radio Surveyor would open this largely-unexplored region of the electromagnetic spectrum with a space-based interferometer to (1)~Track the space weather of other stars; (2)~Detect magnetically-generated emission from exoplanets […]

Kavli Affiliate: Roberto Maiolino | Summary:Ly-alpha emission is widely used to trace cosmic reionization, but its interpretation depends on how Ly-alpha visibility varies with galaxy environment. We use deep JWST/NIRSpec observations from Deep Insights into UV Spectroscopy at the Epoch of Reionization (DIVER) in GOODS-N to measure Ly-alpha visibility for 250 galaxies at 4.8<z<11. The […]

Kavli Affiliate: Roberto Maiolino | Summary:We present JWST/NIRSpec IFU spectroscopy of the central $618times618$ pc$^2$ ($sim3”times3”$) of NGC 4696, the BCG in the Centaurus cluster. Leveraging the $sim0.1”$ ($20.6$ pc) pixel size of JWST, we resolve a compact circumnuclear rotating disk (radius of $sim120$ pc) traced by Pa$α$ and H$_2$ 1$-$0 S(1) emission, which allows […]

Kavli Affiliate: R. G. McMahon | Summary:The Hubble-Lemaître tension remains a significant challenge in modern cosmology, exhibiting a discrepancy between early-Universe cosmic microwave background measurements and local distance ladder observations. Strong lensing time-delay cosmography provides an independent, geometric probe of $H_0$ that can help resolve this discrepancy. Although hundreds of lensed quasars have been discovered, […]

Kavli Affiliate: R. G. McMahon | Summary:The Hubble-Lemaître tension remains a significant challenge in modern cosmology, exhibiting a discrepancy between early-Universe cosmic microwave background measurements and local distance ladder observations. Strong lensing time-delay cosmography provides an independent, geometric probe of $H_0$ that can help resolve this discrepancy. Although hundreds of lensed quasars have been discovered, […]

Kavli Affiliate: Anthony Lasenby | Summary:For the Fierz-Pauli action the Bessel-Hagen construction does not produce a preferred local gauge-invariant energy-momentum tensor; it identifies only a gauge-invariant equivalence class of Noether currents, because the action is built from first derivatives of $h_μν$ whereas the first local gauge-invariant spin-2 field strength, the curvature, contains two. It is […]

Kavli Affiliate: George Efstathiou | Summary:The traditional distance ladder measures the standardized peak absolute magnitude M^B of Type Ia supernovae (SNIa). According to the SH0ES collaboration, the distance ladder value of M^B is highly discrepant with the value inferred from the cosmic microwave background (CMB) assuming the LCDM cosmology. This CMB-distance ladder tension is insensitive […]

Kavli Affiliate: Roberto Maiolino | Summary:Little Red Dots (LRDs) are compact active galactic nuclei (AGN) with unusual spectral energy distributions and broad Balmer emission, candidate signposts of rapid black-hole growth. We present VLT/FORS2 optical linear spectropolarimetry of the closest known LRD, SDSS J102530.29+140207.3, at z=0.1. In total light, we detect spatially extended narrow-H$α$ emission, probably […]

Kavli Affiliate: Blake Sherwin | Summary:Accurate measurements of Cosmic Microwave Background (CMB) B-mode polarization, a key probe of inflationary physics, are hindered by complex Galactic dust foregrounds. Traditional foreground removal with Internal Linear Combination (ILC) fully preserves the primordial signal but requires multi-frequency data and is limited to two-point statistics. We present a novel way […]

Kavli Affiliate: Roberto Maiolino | Summary:The active black holes uncovered by JWST in the early Universe are highly abundant and seemingly overmassive with respect to local scaling relations, challenging standard models of black hole formation and growth. Yet it remains unclear whether they trace an efficient early growth channel, the observable tail of a broader […]