Tootfinder

A Sharp KL-Convergence Analysis for Diffusion Models under Minimal Assumptions
Nishant Jain, Tong Zhang
https://arxiv.org/abs/2508.16306 https://arxiv.org/…

A Sharp KL-Convergence Analysis for Diffusion Models under Minimal Assumptions
Diffusion-based generative models have emerged as highly effective methods for synthesizing high-quality samples. Recent works have focused on analyzing the convergence of their generation process with minimal assumptions, either through reverse SDEs or Probability Flow ODEs. The best known guarantees, without any smoothness assumptions, for the KL divergence so far achieve a linear dependence on the data dimension $d$ and an inverse quadratic dependence on $\varepsilon$. In this work, we prese…

Anisotropic compact star model with quadratic equation of state in paraboloidal spacetime
B S Ratanpal, Bhavesh Suthar
https://arxiv.org/abs/2508.16392 https://

Anisotropic compact star model with quadratic equation of state in paraboloidal spacetime
In this work, we report a new exact solution of Einstein's field equations for static spherically symmetric anisotropic matter distributions on the background of paraboloidal spacetime by assuming a quadratic equation of state. The model parameters were found by matching the interior spacetime metric with the Schwarzschild exterior metric. The new exact solution is non-singular and meets all of the physical plausibility conditions for a realistic compact star. The detailed physical analysis of …

Eine giftige Alge bedroht vor #Südaustralien das #Meeresleben.
Karenia mikimotoi breitet sich massiv aus und verursacht das Sterben hunderter #Tierarten auf über 4.000 Quadratkil…

Giftige Algenblüte bedroht Meerestiere vor Südaustralien
An der Südküste Australiens kommt es derzeit zu einem massenhaften Sterben von Meerestieren. Grund ist eine Alge, die sich dort stark ausbreitet. Es herrscht Verzweiflung und Fassungslosigkeit.

Tunable phase transitions from semimetals to Chern insulators in two-dimensional quadratic-band-crossing materials
Wen-Hao Bian, Jing Wang
https://arxiv.org/abs/2506.19378

Tunable phase transitions from semimetals to Chern insulators in two-dimensional quadratic-band-crossing materials
We systematically investigate how static symmetry-breaking perturbations and dynamic Floquet terms via a polarized light manipulate the topological phase transitions in the two-dimensional quadratic-band-crossing-point (QBCP) materials. The Berry curvature shows distinct behavior in such two situations. It is linearly and quadratically proportional to the product of microstructural parameters $t_{x,z}$ for the former and the latter, respectively. The static perturbation eliminates the QBCP and …

The LQR-Schr\"odinger Bridge
Marc Lambert (SIERRA)
https://arxiv.org/abs/2506.17273 https://arxiv.org/pdf/2506.17273

The LQR-Schrödinger Bridge
We consider the Schr{ö}dinger bridge problem in discrete time, where the pathwise cost is replaced by a sum of quadratic functions, taking the form of a linear quadratic regulator (LQR) cost. This cost comprises potential terms that act as attractors and kinetic terms that control the diffusion of the process. When the two boundary marginals are Gaussian, we show that the LQR-Schr{ö}dinger bridge problem can be solved in closed form. We follow the dynamic programming principle, interpreting t…

Precision Matrix Regularization in Sufficient Dimension Reduction for Improved Quadratic Discriminant Classification
Derik T. Boonstra, Rakheon Kim, Dean M. Young
https://arxiv.org/abs/2506.19192

Precision Matrix Regularization in Sufficient Dimension Reduction for Improved Quadratic Discriminant Classification
Sufficient dimension reduction (SDR) methods, which often rely on class precision matrices, are widely used in supervised statistical classification problems. However, when class-specific sample sizes are small relative to the original feature-space dimension, precision matrix estimation becomes unstable and, as a result, increases the variability of the linear dimension reduction (LDR) matrix. Ultimately, this fact causes suboptimal supervised classification. To address this problem, we develo…

from my link log —
The tar archive format, its extensions, and why GNU tar extracts in quadratic time.
https://mort.coffee/home/tar/
saved 2025-07-03 http…

Spectral Outer-Approximation Algorithms for Binary Semidefinite Problems
Daniel de Roux, Zedong Peng, David E. Bernal Neira
https://arxiv.org/abs/2506.18265

Spectral Outer-Approximation Algorithms for Binary Semidefinite Problems
Integer semidefinite programming (ISDP) has recently gained attention due to its connection to binary quadratically constrained quadratic programs (BQCQPs), which can be exactly reformulated as binary semidefinite programs (BSDPs). However, it remains unclear whether this reformulation effectively uses existing ISDP solvers to address BQCQPs. To the best of our knowledge, no specialized ISDP algorithms exploit the unique structure of BSDPs derived from BQCQPs. This paper proposes a novel spectr…

Accelerating Expansion of the Universe in modified gravity with quadratic terms
Aaqid Bhat
https://arxiv.org/abs/2507.17794 https://arxiv.org/pdf/2507.1779…

Accelerating Expansion of the Universe in modified gravity with quadratic terms
Chapter1 introduces cosmic acceleration and outlines key features and limitations of GR and its alternatives, including teleparallel and symmetric teleparallel gravity. In Chapter2, we analyze the cosmological implications of $f(T,\mathcal{T})$ theory by considering the squared-torsion model $f(T,\mathcal{T})= α\mathcal{T}+ βT^2$, where $T$ represents torsion and $\mathcal{T}$ is the trace of the energy-momentum tensor. In Chapter3, we explore the inflationary scenario within the framework of…

General Linear-Quadratic Mean Field Stochastic Differential Game with Common Noise: a Direct Method
Yu Si, Jingtao Shi
https://arxiv.org/abs/2506.16779 htt…

General Linear-Quadratic Mean Field Stochastic Differential Game with Common Noise: a Direct Method
This paper investigates a class of general linear-quadratic mean field games with common noise, where the diffusion terms of the system contain the state variables, control variables, and the average state terms. We solve the problem using both the direct method and the fixed-point method in the paper. First, by using the variational method to solve a finite $N$-players game problem, we obtain the necessary and sufficient conditions for the centralized open-loop Nash equilibrium strategy. Subse…