Piezoelectric resonators in thin-film barium titanate from room temperature to millikelvin

Posted by klaurent Caltech

Kavli Affiliate: Mohammad Mirhosseini | Summary:Ferroelectric materials, with their strong nonlinearities, underpin key technologies across radio-frequency (RF) signal processing, optical communications, and emerging quantum systems. Barium titanate (BTO) is a notable example, combining strong piezoelectric and electro-optic responses. While bulk BTO has been studied for decades, the piezoelectric properties of its recently available thin films, […]


Continue.. Piezoelectric resonators in thin-film barium titanate from room temperature to millikelvin

Reconstructing Galactic Gravitational Potentials from Stellar Kinematics with Physics-Informed Neural Networks

Posted by klaurent MIT

Kavli Affiliate: Lina Necib | Summary:The gravitational potential of a galaxy encodes its mass distribution, formation history, and dark matter halo structure. Accurate potential models are therefore critical for interpreting stellar kinematics, orbital dynamics, and the influence of satellite systems like the Large Magellanic Cloud. Analytic potential models offer interpretability and efficiency but struggle to […]


Continue.. Reconstructing Galactic Gravitational Potentials from Stellar Kinematics with Physics-Informed Neural Networks

The Lumina Project: Intergalactic Clumping and Recombination Sinks

Posted by klaurent MIT

Kavli Affiliate: Mark Vogelsberger | Summary:Recombinations during the Epoch of Reionization are intrinsically inhomogeneous, with different regions of the intergalactic medium contributing unevenly depending on their density, temperature, ionization state, and spatial patchiness. We combine the high- and medium-resolution 95.5 cMpc Thesan-1 andh Thesan-2 runs with the significantly larger 500 cMpc Lumina simulation to measure […]


Continue.. The Lumina Project: Intergalactic Clumping and Recombination Sinks

RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

Posted by klaurent Peking

Kavli Affiliate: Xian Chen| Summary: Graph-based retrieval at billion-node scale requires jointly solving three tightly coupled problems — graph construction, representation learning, and real-time serving — yet existing work addresses each in isolation. We present RankGraph-2, a framework deployed at Meta that co-designs all three lifecycle stages for similarity-based retrieval (U2U2I and U2I2I), where each […]


Continue.. RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

Posted by klaurent Peking

Kavli Affiliate: Xian Chen| Summary: Graph-based retrieval at billion-node scale requires jointly solving three tightly coupled problems — graph construction, representation learning, and real-time serving — yet existing work addresses each in isolation. We present RankGraph-2, a framework deployed at Meta that co-designs all three lifecycle stages for similarity-based retrieval (U2U2I and U2I2I), where each […]


Continue.. RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

Posted by klaurent Peking

Kavli Affiliate: Xian Chen| Summary: Graph-based retrieval at billion-node scale requires jointly solving three tightly coupled problems — graph construction, representation learning, and real-time serving — yet existing work addresses each in isolation. We present RankGraph-2, a framework deployed at Meta that co-designs all three lifecycle stages for similarity-based retrieval (U2U2I and U2I2I), where each […]


Continue.. RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

Posted by klaurent Peking

Kavli Affiliate: Xian Chen| Summary: Graph-based retrieval at billion-node scale requires jointly solving three tightly coupled problems — graph construction, representation learning, and real-time serving — yet existing work addresses each in isolation. We present RankGraph-2, a framework deployed at Meta that co-designs all three lifecycle stages for similarity-based retrieval (U2U2I and U2I2I), where each […]


Continue.. RankGraph-2: Lifecycle Co-Design for Billion-Node Graph Learning in Recommendation

Do Time Series Foundation Model Benchmarks Hide Regime-Dependent Failures? Evidence from Traffic Speed Forecasting

Posted by klaurent Caltech

Kavli Affiliate: Wei Gao| Summary:Standard benchmarks evaluate time series foundation models (TSFMs) using aggregate metrics, but these can mask severe failures in critical operating regimes. We introduce regime-stratified evaluation and apply it to three TSFMs on two standard traffic speed benchmarks. Traffic exhibits abrupt regime switching between free-flow and congested states, producing bimodal speed distributions […]


Continue.. Do Time Series Foundation Model Benchmarks Hide Regime-Dependent Failures? Evidence from Traffic Speed Forecasting

Do Time Series Foundation Model Benchmarks Hide Regime-Dependent Failures? Evidence from Traffic Speed Forecasting

Posted by klaurent Caltech

Kavli Affiliate: Wei Gao| Summary:Standard benchmarks evaluate time series foundation models (TSFMs) using aggregate metrics, but these can mask severe failures in critical operating regimes. We introduce regime-stratified evaluation and apply it to three TSFMs on two standard traffic speed benchmarks. Traffic exhibits abrupt regime switching between free-flow and congested states, producing bimodal speed distributions […]


Continue.. Do Time Series Foundation Model Benchmarks Hide Regime-Dependent Failures? Evidence from Traffic Speed Forecasting

Coordination of turn-related activity in the superior colliculus with locomotor dynamics and hippocampal representations of possible futures

Posted by dbos UCSD / Salk

Kavli Affiliate: Massimo Scanziani and Loren Frank | Authors: Cameron Wilhite, Loren M. Frank and Massimo Scanziani | Summary: Turning left or right is a core element of animal navigation. Such turns occur in precise coordination with the ongoing stepping rhythm and require internal planning for the animal’s future path. The superior colliculus (SC) is […]


Continue.. Coordination of turn-related activity in the superior colliculus with locomotor dynamics and hippocampal representations of possible futures