ALT A colorful 3D reconstruction of a connectome shows the map of over 166,000 neurons and 125 million connections in a male fruit fly's brain and nerve cord.

ALT A fruit fly connectome map text with scattered fruit fly images. The text reads: "With it, we can compare our new map to other connectomes of the female fly brain, including our 2020 hemibrain project with partners. Having maps for both fruit fly sexes allows researchers to pinpoint exact structural brain differences and study how they drive specific biological behaviors.”

ALT A 3D visualization of a fruit fly brain map in vibrant colors is shown alongside text explaining how mapping fruit fly nervous systems using AI helps us understand brain function and neural repair.

ALT A colourful 3D brain connectivity map shown alongside text about mapping neurons in fruit flies to better understand human brains.

ALT In grokking an early fit to the training data separates from a much later improvement in generalization. During this delay, training can move from a fixed neural tangent kernel (NTK) regime to one in which task-relevant kernel eigendirections continue to evolve. We provide a quantitative theory for how this transition from lazy to rich learning can produce delayed generalization. For homogeneous networks trained with squared loss and L₂ weight decay, we show that a finite residual remains after memorization, with larger residual fractions in target components associated with smaller NTK eigenvalues. These residuals feed back into the dynamics of the NTK itself, and projecting the resulting dynamics onto task-relevant spectral directions yields a reduced system in which residual-driven kernel growth competes with weight decay. This system predicts that the grokking timescale is controlled by the product of learning rate and weight decay, that feature learning slows logarithmically near

ALT We present a new Plebanski formulation of General Relativity. The key difference is that we work with a gauge vector field derived from the Lanczos potential of the Weyl tensor. We show that, on shell, the gauge vector field encodes all nontrivial gravitational degrees of freedom and, in a suitable Lorentz gauge, Bianchi identities ensure that this gauge vector field satisfies a source-free wave equation for Ricci-flat spacetimes. This description suggests new ways of interpreting the true geometrical degrees of freedom with applications in both classical and quantum gravity.

ALT A plot of longitudinal resistance versus magnetic field strength up to nearly 70 teslas shows a blue and a black line curving upward. An inset at the bottom right shows a close-up of the line, revealing four vertically offset lines (blue, purple, pink, and black) of measurements taken at different temperatures: 16, 10, 6, and 2, respectively. A second inset at the top left shows a scanning electron microscope image of a blocky and channeled 3D surface of the microstructure of the tested material. A false color overlay shows gold areas indicating contacts (labeled V1, V2, V3, and V4) and purple regions where the chromium antimonide is located. A white arrow labeled a’ indicates the direction of current application. A scale bar at the bottom, roughly the size of a single contact, measures 10 micrometers.