Tootfinder

🇺🇦 #NowPlaying on BBCRadio3's #LateJunction
Karl Burke:
🎵 Cage on a Stage
#KarlBurke

Lower estimates for the norm and the Kuratowski measure of moncompactness of Wiener-Hopf type operators
Oleksiy Karlovych, Eugene Shargorodsky
https://arxiv.org/abs/2509.20296 h…

Lower estimates for the norm and the Kuratowski measure of moncompactness of Wiener-Hopf type operators
Let $X(\mathbb{R}^n)$ be a Banach function space and $Ω\subseteq\mathbb{R}^n$ be a measurable set of positive measure. For a Fourier mutliplier $a$ on $X(\mathbb{R}^n)$, consider the Wiener-Hopf type operator $W_Ω(a):=r_ΩF^{-1}aF e_Ω$, where $F^{\pm 1}$ are the Fourier transforms, $r_Ω$ is the operator of restriction from $\mathbb{R}^n$ to $Ω$ and $e_Ω$ is the operator of extension by zero from $Ω$ to $\mathbb{R}^n$. Let $X_2(Ω)$ be the closure of $L^2(Ω)\cap X(Ω)$ in $X(Ω)$. We sho…

🇺🇦 #NowPlaying on KEXP's #MiddayShow
Kurilpa Reach:
🎵 The Mountain
#KurilpaReach
https://kurilpareach.bandcamp.com/track/the-mountain
https://open.spotify.com/track/2lnBBhGZXQyPfzo0p6SvQY

I'm going home - the master version.
#karlbushby

Randomized flexible Krylov methods for $\ell_p$ regularization
Malena Sabat\'e Landman, Yuji Nakatsukasa
https://arxiv.org/abs/2510.11237 https://arxiv…

Randomized flexible Krylov methods for $\ell_p$ regularization
The computation of sparse solutions of large-scale linear discrete ill-posed problems remains a computationally demanding task. A powerful framework in this context is the use of iteratively reweighted schemes, which are based on constructing a sequence of quadratic tangent majorants of the $\ell_2$-$\ell_1$ regularization functional (with additional smoothing to ensure differentiability at the origin), and solving them successively. Recently, flexible Krylov-Tikhonov methods have been used to …

Tangent space Krylov computation of real-frequency spectral functions: Influence of density-assisted hopping on 2D Mott physics
Oleksandra Kovalska, Jan von Delft, Andreas Gleis
https://arxiv.org/abs/2510.07279

Tangent space Krylov computation of real-frequency spectral functions: Influence of density-assisted hopping on 2D Mott physics
We present a tangent-space Krylov (TaSK) method for efficient computation of zero-temperature real-frequency spectral functions on top of ground state (GS) matrix product states (MPS) obtained from the Density Matrix Renormalization Group. It relies on projecting resolvents to the tangent space of the GS-MPS, where they can be efficiently represented using Krylov space techniques. This allows for a direct computation of spectral weights and their corresponding positions on the real-frequency ax…

An inexact semismooth Newton-Krylov method for semilinear elliptic optimal control problem
Shiqi Chen, Xuesong Chen
https://arxiv.org/abs/2511.10058 https://arxiv.org/pdf/2511.10058 https://arxiv.org/html/2511.10058
arXiv:2511.10058v1 Announce Type: new
Abstract: An inexact semismooth Newton method has been proposed for solving semi-linear elliptic optimal control problems in this paper. This method incorporates the generalized minimal residual (GMRES) method, a type of Krylov subspace method, to solve the Newton equations and utilizes nonmonotonic line search to adjust the iteration step size. The original problem is reformulated into a nonlinear equation through variational inequality principles and discretized using a second-order finite difference scheme. By leveraging slanting differentiability, the algorithm constructs semismooth Newton directions and employs GMRES method to inexactly solve the Newton equations, significantly reducing computational overhead. A dynamic nonmonotonic line search strategy is introduced to adjust stepsizes adaptively, ensuring global convergence while overcoming local stagnation. Theoretical analysis demonstrates that the algorithm achieves superlinear convergence near optimal solutions when the residual control parameter $\eta_k$ approaches to 0. Numerical experiments validate the method's accuracy and efficiency in solving semilinear elliptic optimal control problems, corroborating theoretical insights.
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RE: #notThatJesus
No, we don't follow that Jesus, we follow the Jesus of the old testa…

Und ich bin gar nicht mal so gespannt, ob das in deutschen Medien einen ähnlichen Aufruhr auslöst wie irgendeine Gruppierung der Linken in Berlin, die vermeintlich irgendeine rechtsradikale Drecksschleuder angegriffen hat.
https://bsky.brid.gy/r/https://bsky.a…

🇺🇦 #NowPlaying on BBCRadio3's #ThroughTheNight
Karel Vrtiska & Bedřich Smetana:
🎵 2 Dances (Czech Dances, Book II)
#KarelVrtiska #BedřichSmetana