Tootfinder

Approximation of pseudohermitian structures via embeddings into spheres
Hendrik Herrmann, Chin-Yu Hsiao, Bernhard Lamel
https://arxiv.org/abs/2506.14033 ht…

Approximation of pseudohermitian structures via embeddings into spheres
Let $(X,T^{1,0}X)$ be a compact strictly pseudoconvex CR manifold which is CR embeddable into the complex Euclidean space. We show that $T^{1,0}X$ can be approximated in $\mathscr{C}^\infty$-topology by a sequence of strictly pseudoconvex CR structures $\{\mathcal{V}^k\}_{k\in \mathbb N}$ such that each $(X,\mathcal{V}^k)$ is CR embeddable into the unit sphere of a complex Euclidean space. Furthermore, as a refinement of this statement, we show that given a one form $α$ on $X$ such that $(X,T^…

JWST observations of the Ring Nebula (NGC 6720) -- II. PAH emission
Nicholas Clark, Els Peeters, Nick L. J. Cox, Jan Cami, Michael J. Barlow, Patrick J. Kavanagh, Griet Van de Steene, Mikako Matsuura, Albert Zijlstra, Isabel Aleman, Jeronimo Bernard-Salas, Harriet L. Dinerstein, Kay Justtanont, Kyle F. Kaplan, Arturo Manchado, Raghvendra Sahai, Peter van Hoof, Kevin Volk, Roger Wesson

JWST observations of the Ring Nebula (NGC 6720) -- II. PAH emission
Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous dust have been observed in clumpy circumstellar environments, yet their formation and evolutionary pathways in such environments remain elusive. We aim to characterize the PAH emission in a clumpy planetary nebula to decipher their formation and evolution pathways. We obtained JWST Near-Infrared Spectrograph (NIRSpec) and Mid-Infrared Instrument (MIRI) integral field unit spectroscopic observations of two individual knots in the Ring Nebu…

All-Dielectric Metasurface with a Two-Dimensional Locally Flat Photonic Band
Minho Choi, Christopher Munley, Arnab Manna, Johannes Fr\"och, Arthur Barnard, Arka Majumdar
https://arxiv.org/abs/2506.20871

All-Dielectric Metasurface with a Two-Dimensional Locally Flat Photonic Band
Photonic flatbands offer promising light-matter interaction due to their unique slow-light nature. In recent years, flatbands have also attracted significant interest in optical engineering because of their angle-insensitive resonant characteristics. However, most photonic flatbands demonstrated to date occur only in one dimension and for a specific polarization, limiting their applicability. To date, no studies have reported the dispersionless behavior of flatbands under arbitrary two-dimensio…