Kavli Affiliate: Max Tegmark | Summary:Large language models are beginning to show steganographic capabilities. Such capabilities could allow misaligned models to evade oversight mechanisms. Yet principled methods to detect and quantify such behaviours are lacking. Classical definitions of steganography, and detection methods based on them, require a known reference distribution of non-steganographic signals. For the […]

Kavli Affiliate: Max Tegmark | Summary:Large language models are beginning to show steganographic capabilities. Such capabilities could allow misaligned models to evade oversight mechanisms. Yet principled methods to detect and quantify such behaviours are lacking. Classical definitions of steganography, and detection methods based on them, require a known reference distribution of non-steganographic signals. For the […]

Kavli Affiliate: Max Tegmark | Summary:Large language models are beginning to show steganographic capabilities. Such capabilities could allow misaligned models to evade oversight mechanisms. Yet principled methods to detect and quantify such behaviours are lacking. Classical definitions of steganography, and detection methods based on them, require a known reference distribution of non-steganographic signals. For the […]

Kavli Affiliate: Erin Kara | Summary:The supermassive binary system, $η$ Carinae, is experiencing enormous wind-driven mass loss at a rate unparalleled in the rest of the Galaxy. Their wind-wind collision (WWC) continuously produces shock heated, X-ray emitting plasmas. The XRISM X-ray observatory observed the system in 2023 and 2024 when the X-ray emission began to […]

Kavli Affiliate: Kiyoshi Masui | Summary:We present the discovery and subsequent 3.2 year monitoring campaign of the repeating fast radio burst FRB 20220529A with CHIME/FRB. We observe a gradual dispersion measure (DM) decline of $-0.881pm0.001~mathrmpc~mathrmcm^-3~mathrmyear^-1$ ($-1.235pm0.001~mathrmpc~mathrmcm^-3~mathrmyear^-1$ in the rest frame), implying a $geq3.5pm0.2$% decrease of the total electron column in the source environment, and we […]

Kavli Affiliate: Kiyoshi Masui | Summary:We present the discovery and subsequent 3.2 year monitoring campaign of the repeating fast radio burst FRB 20220529A with CHIME/FRB. We observe a gradual dispersion measure (DM) decline of $-0.881pm0.001~mathrmpc~mathrmcm^-3~mathrmyear^-1$ ($-1.235pm0.001~mathrmpc~mathrmcm^-3~mathrmyear^-1$ in the rest frame), implying a $geq3.5pm0.2$% decrease of the total electron column in the source environment, and we […]

Kavli Affiliate: Dheeraj Pasham | Summary:We study AT2024kmq and AT2024lhc, two tidal disruption events (TDEs) with blue featureless spectra associated with high-mass black holes ($M_rm BHsim 10^8,M_odot$). Both events show optical precursors consistent with shock dissipation from stream self-intersection. Their X-ray emission is luminous ($L_rm Xsim 10^44,rm erg,s^-1$), highly variable (with minimum observed variability timescales […]

Kavli Affiliate: Salvatore Vitale | Summary:As gravitational-wave catalogs grow, they will become increasingly computationally expensive to analyze in their entirety, especially when inferring astrophysical source populations with high-dimensional, flexible models. Bayesian statistics offers a natural remedy, letting us update our knowledge of physical models as new data arrive, without re-analyzing existing data. However, doing so […]

Kavli Affiliate: Sara Seager | Summary:We characterize the radius-dependent eccentricity distribution of 347 warm (P = 8-200 days) systems with only one transiting planetary candidate identified during Sectors 1-69 of the TESS mission. Using the “photoeccentric effect” in a hierarchical Bayesian framework, we first model the population using discrete planetary size bins (sub-Neptunes, sub-Saturns, and […]

Kavli Affiliate: Kiyoshi Masui | Summary:Quantifying the maximum energy of fast radio bursts (FRBs) can provide stringent constraints on their emission mechanisms and progenitor models. However, the most energetic bursts are rare, requiring a large sample of FRBs to detect them. In this work, we use the largest available such sample, 2,998 one-off FRBs from […]