Tootfinder

This https://arxiv.org/abs/2404.03026 has been replaced.
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The Magic Number Conjecture for the $m=2$ amplituhedron and Parke-Taylor identities
The amplituhedron $A_{n,k,m}$ is a geometric object introduced in the context of scattering amplitudes in $N=4$ super Yang Mills. It generalizes the positive Grassmannian (when $n=k+m$), cyclic polytopes (when $k=1$), and the bounded complex of the cyclic hyperplane arrangement (when $m=1$). Of substantial interest are the tilings of the amplituhedron, which are analogous to triangulations of a polytope. Karp, Williams and Zhang (2020) observed that the known tilings of $A_{n,k,2}$ have cardina…

Lightning-Fast Thunderstorm Warnings: Predicting Severe Convective Environments with Global Neural Weather Models
Monika Feldmann, Tom Beucler, Milton Gomez, Olivia Martius
https://arxiv.org/abs/2406.09474

Lightning-Fast Thunderstorm Warnings: Predicting Severe Convective Environments with Global Neural Weather Models
The recently released suite of AI weather models can produce multi-day, medium-range forecasts within seconds, with a skill on par with state-of-the-art operational forecasts. Traditional AI model evaluation predominantly targets global scores on single levels. Specific prediction tasks, such as severe convective environments, require much more precision on a local scale and with the correct vertical gradients between levels. With a focus on the convective season of global hotspots in 2020, we …

X-Ray spectral and temporal properties of LMXB 4U 1608-52- observed with AstroSat and NICER
Sree Bhattacherjee, Ankur Nath, Biplob Sarkar, Aru Beri, Suchismito Chattopadhyay, Yashpal Bhulla, Ranjeev Misra
https://arxiv.org/abs/2406.10666

X-Ray spectral and temporal properties of LMXB 4U 1608-52- observed with AstroSat and NICER
We report results from a detailed study of the neutron star X-ray binary, 4U 1608-52 using observations with {\it AstroSat} (LAXPC/SXT) and {\it NICER} during its 2016 and 2020 outbursts. The 0.7--20.0 keV spectra could be well described with the disk blackbody and thermal Comptonization model. The best-fitting inner disk temperature is $\sim$ 1 keV and radius { $\sim$ 22.17$^{+2.57}_{-2.38}$--27.19$^{+2.03}_{-1.85}$} km and no significant evolution was observed in the disk radius after perform…

Elasticity of fibres prefers the chaos of turbulence
Rahul K. Singh
https://arxiv.org/abs/2406.06033 https://arxiv.org/pdf/2406.06033…

Elasticity of fibres prefers the chaos of turbulence
The dynamics of fibres, modelled as a sequence of inertial beads linked via elastic springs, in turbulent flows is dictated by a non-trivial interplay of their inertia and elasticity. Such elastic, inertial fibres preferentially sample a three-dimensional turbulent flow in a manner qualitatively similar to that in two-dimensions [Singh et al., Phys. Rev. E 101, 053105 (2020)]. Inertia and elasticity have competing effects on fibre dynamics: Inertia drives fibres away from vortices while elastic…

Lightning-Fast Thunderstorm Warnings: Predicting Severe Convective Environments with Global Neural Weather Models
Monika Feldmann, Tom Beucler, Milton Gomez, Olivia Martius
https://arxiv.org/abs/2406.09474

Lightning-Fast Thunderstorm Warnings: Predicting Severe Convective Environments with Global Neural Weather Models
The recently released suite of AI weather models can produce multi-day, medium-range forecasts within seconds, with a skill on par with state-of-the-art operational forecasts. Traditional AI model evaluation predominantly targets global scores on single levels. Specific prediction tasks, such as severe convective environments, require much more precision on a local scale and with the correct vertical gradients between levels. With a focus on the convective season of global hotspots in 2020, we …

Identification of cross-frequency interactions in compressible cavity flow using harmonic resolvent analysis
Md Rashidul Islam, Yiyang Sun
https://arxiv.org/abs/2406.07705

Identification of cross-frequency interactions in compressible cavity flow using harmonic resolvent analysis
The resolvent analysis reveals the worst-case disturbances and the most amplified response in a fluid flow that can develop around a stationary base state. The recent work by Padovan et al.(2020) extended the classical resolvent analysis to the harmonic resolvent analysis framework by incorporating the time-varying nature of the base flow. The harmonic resolvent analysis can capture the triadic interactions between perturbations at two different frequencies through a base flow at a particular f…