Tootfinder

Ricci Solitons, Almost Theta-Yamabe Solitons, and Finite-Order Tensor Symmetries of a Vector Field on Riemannian Manifolds with Rank-One Anisotropic Curvature
Abdou Bousso, Ameth Ndiaye
https://arxiv.org/abs/2609.14866 https://arxiv.org/pdf/2609.14866 https://arxiv.org/html/2609.14866
arXiv:2609.14866v1 Announce Type: new
Abstract: We study the iterated action of the Lie derivative on the curvature tensor of a Riemannian manifold with rank-one anisotropic curvature, whose Riemann tensor is expressed via the Kulkarni-Nomizu product as $R = \lambda (\xi^\flat\otimes\xi^\flat)\owedge g$. First, we examine the conditions under which such a manifold admits a Ricci soliton structure and demonstrate that this property implies the almost $\theta$-Yamabe soliton structure. Furthermore, we show that if the associated potential vector field $X$ is a symmetry of the Ricci tensor of a fixed order $k$ (i.e., $\mathcal{L}_X^k \operatorname{Ric} = 0$), the geometric problem reduces to solving a partial differential equation of order $k 1$ along the flow. Finally, under the assumption that $X$ is a conformal vector field ($\mathcal{L}_X g = 2\varphi g$) whose infinitesimal flow preserves the line distribution $\mathcal{D}=\operatorname{Span}\{\xi\}$ (with $[X,\xi]=a\xi$ for $a\in\mathbb{R}$), we prove that several key geometric problems (such as establishing the relation $\mathcal{L}_X^k R = R$, determining the minimal order $k$ for $X$ to be a Lie curvature symmetry, or satisfying $\mathcal{L}_X^{k 1}R = f \mathcal{L}_X^k R$ for a continuous function $f$) are equivalent to a scalar differential problem governed by the operator $D_X = X 6\varphi 2a$.
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Feature-Guided Diffusion for Non-Differentiable Inverse Rendering
Andrei-Timotei Ardelean, Michael Fischer, Tim Weyrich, Tom\'a\v{s} Iser
https://arxiv.org/abs/2607.17411 https://arxiv.org/pdf/2607.17411 https://arxiv.org/html/2607.17411
arXiv:2607.17411v1 Announce Type: new
Abstract: Inverse rendering is traditionally solved via differentiable renderers and gradient descent, which requires substantial problem-specific engineering and is prone to getting stuck in local minima due to ambiguities. Derivative-free approaches alleviate engineering requirements, but often heavily depend on a good problem initialization. In this work, we propose Feature-Informed Diffusion Evolution (FIDE), a fully black-box framework that requires no gradients or specific initialization: the renderer is treated as an opaque function whose only requirement is to produce images. Our key insight is feature guiding: rather than reducing each candidate rendering to a scalar loss value, we use a Vision Transformer (ViT) to extract dense visual features from it. We subsequently use these features to train a diffusion-based candidate proposal model, allowing the network to use visual cues to predict parameters that would match the target image. The candidate solutions proposed by this diffusion model are then refined in a closed loop with a CMA evolution strategy, continuously narrowing the proposal region as optimization progresses. We validate across diverse inverse problems from path tracing, vector splines, Voronoi shaders, and robotics, and demonstrate that feature-guiding substantially improves convergence over scalar-loss baselines and reliably escapes local minima where gradient-based methods stall.
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Replaced article(s) found for hep-th. https://arxiv.org/list/hep-th/new
[2/3]:
- Toward an Observable Algebra for de Sitter Space: Gap Protection and Modular Dressings
Hassan ElSayed
https://arxiv.org/abs/2607.26194 https://mastoxiv.page/@arXiv_hepth_bot/117007888988009612
- Extended Scalar Particle Solutions in Black String Spacetimes with Anisotropic Quintessence
M. L. Deglmann, B. V. Sim\~ao, C. C. Barros Jr
https://arxiv.org/abs/2504.17765 https://mastoxiv.page/@arXiv_grqc_bot/114397428123774125
- Universal supercritical thermodynamics for black holes
Shoucheng Wang, Xinyang Li, Yuliang Jin, Li Li
https://arxiv.org/abs/2506.10808 https://mastoxiv.page/@arXiv_grqc_bot/114675464316469493
- Running Quantum Computers in Discovery Mode
Aydin Deger, Benedikt Placke, G. J. Sreejith, Alessio Lerose, S. L. Sondhi
https://arxiv.org/abs/2507.01013 https://mastoxiv.page/@arXiv_quantph_bot/114783153034025740
- Full Eigenstate Thermalization in Integrable Spin Systems
Tanay Pathak
https://arxiv.org/abs/2510.05887 https://mastoxiv.page/@arXiv_condmatstatmech_bot/115337676705890347
- Boundary structure of gauge fields on asymptotically AdS spaces
Maxim Grigoriev, Mikhail Markov
https://arxiv.org/abs/2512.06576 https://mastoxiv.page/@arXiv_mathph_bot/115688746382829511
- Improved frequency hierarchy treatment for anisotropic spectral distortions
Jens Chluba, Sara Evangelista, Tom Daman, Geoff Vasil
https://arxiv.org/abs/2602.14963 https://mastoxiv.page/@arXiv_astrophCO_bot/116085543680916118
- Black-Hole Microstate Hair Requires a Horizon Measurement
Sudhanva Joshi, Sunil Kumar Mishra
https://arxiv.org/abs/2604.28050 https://mastoxiv.page/@arXiv_quantph_bot/116498398591886253
- Unified dark sector and Hubble-tension alleviation in scalar-vector-tensor gravity
Kimet Jusufi, Amir A. Khodahami, Ahmad Sheykhi, Jackson Levi Said, Emmanuel N. Saridakis
https://arxiv.org/abs/2605.14977 https://mastoxiv.page/@arXiv_grqc_bot/116577642488987255
- Exact spectrum and anomalous relaxation in the open disorder-free Sachdev-Ye-Kitaev system
Soshun Ozaki, Hironobu Yoshida, Hosho Katsura
https://arxiv.org/abs/2606.08079 https://mastoxiv.page/@arXiv_condmatstrel_bot/116719187444301432
- Energy Flux as an Entanglement Current in Moving-Mirror Radiation
Yasusada Nambu, Riku Yoshimoto
https://arxiv.org/abs/2607.19763 https://mastoxiv.page/@arXiv_grqc_bot/116968262813501741
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Sharp proper estimation of fixed-component Gaussian location mixtures in polynomial time
Hengzhi He, Guang Cheng
https://arxiv.org/abs/2608.12701 https://arxiv.org/pdf/2608.12701 https://arxiv.org/html/2608.12701
arXiv:2608.12701v1 Announce Type: new
Abstract: We consider a mixture of at most $k$ unit-covariance Gaussians in $\mathbb{R}^d$ whose means belong to a fixed-radius ball, with no separation or minimum-weight condition. Doss, Wu, Yang and Zhou (2023) proved that the minimax Hellinger risk is of order $\sqrt{d/n}\wedge 1$ and constructed a proper polynomial-time estimator with the slower general bound $(d/n)^{1/4}$; obtaining the sharp rate in polynomial time for fixed $k\geq 3$ was left open. We resolve this question. The key device is a moment-fiber range finder. A second-moment subspace controls the energy missed by projection. We then estimate finitely many one-free-index Hermite contractions. These vector-valued contractions recover every tensor component containing exactly one missed direction at the sharp $\sqrt{d/n}$ scale. Every remaining term contains at least two missed factors and is therefore controlled by the residual second-moment energy. The resulting subspace has dimension depending only on $k$. Exhaustive moment fitting in this constant-dimensional space produces a proper mixture and, together with the dimension-free moment characterization of Gaussian mixtures, achieves the optimal Hellinger rate in polynomial arithmetic time for every fixed $k$.
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From Flows to Maps: Sampling Laws for Attractor Intensity and Bounded-Noise Escape
Jiguang Yu, Louis Shuo Wang
https://arxiv.org/abs/2608.02933 https://arxiv.org/pdf/2608.02933 https://arxiv.org/html/2608.02933
arXiv:2608.02933v1 Announce Type: new
Abstract: Intensity of attraction quantifies the largest amplitude of a persistent bounded disturbance that an attractor can withstand without loss of controlled confinement in its basin. Although intensity has been formulated separately for flows and maps, its behavior under temporal sampling has remained unresolved. We establish an explicit correspondence between the intensity $\mu(A)$ of a continuous-time attractor and the intensity $\mu_h(A)$ of its exact time-$h$ map. For an $L$-Lipschitz vector field, \[ \frac{\mu(A)}{1 Lh} \leq \frac{\mu_h(A)}{h} \leq \mu(A)\frac{e^{Lh}-1}{Lh}, \] and hence $\mu_h(A)/h\to\mu(A)$. The resulting first-order rate is sharp in general, while smooth scalar escape geometries can exhibit second-order convergence. We extend the framework to one-step numerical methods through a stability theory for block intensity and to attracting invariant graphs over compact invertible nonautonomous bases, obtaining uniform sampling convergence over the forcing phase. For bounded-support random perturbations, normalized discrete intensity is identified with the pathwise safety threshold; above it, finite escape follows under an explicit finite-exit condition, while escape probabilities require additional assumptions on the noise law. We also show that the discrete state--normal boundary map converges to the normalized Pontryagin boundary system governing extremal reachable-set boundaries. Exact scalar benchmarks, a grazing resilience model, planar Duffing escape, anisotropic disturbances, periodic and quasiperiodic forcing, and transfer-operator computations illustrate the theory. These results give intensity estimated from discrete observations or simulations a sampling-independent continuous-time meaning.
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A most #unbelievable #Friday:
1. A scholar extraordinaire called *me* to inquire of my health. 1.5 years ago, I sat in his lectures, him not knowing I even existed. 🙇‍♂️
2. Visited friends. Another visitor there is actually my first cousin who I hadn't seen in 3 decades. 😲
3. Someone extremely important and influential called and I didn't recognize it was them. So, now I'm looking for means to convey my apologies and ask forgiveness. 😳
#life #gratitude #blessings

K-contact manifolds admitting some geometric solitons with Semi-Symmetric Non-Metric Connection
Bidhan Mondal, Nirabhra Basu, Arindam Bhattacharyya
https://arxiv.org/abs/2609.15147 https://arxiv.org/pdf/2609.15147 https://arxiv.org/html/2609.15147
arXiv:2609.15147v1 Announce Type: new
Abstract: In this paper, we introduce some type vector fields with respect to a semi-symmetric non-metric (SSNM) connection. We investigate several geometric properties of a K-contact manifold equipped with an SSNM connection and provide a concrete example to justify the relation between the scalar curvature of the SSNM connection and Levi-Civita connection that we have obtained in this paper. Furthermore, we have found the nature of Riemann solitons, conformal Ricci solitons and conformal $\eta$-Ricci-Yamabe solitons on K-contact manifolds admitting a SSNM connection.\\ Finally, we determine the necessary and sufficient conditions for such a manifold to be $\Tilde{\tau}$-semi-symmetric, quasi-conformal-semi-symmetric and pseudo-projective-semi-symmetric.
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Empirical likelihood confidence regions for ordered bivariate means
Naresh Garg
https://arxiv.org/abs/2608.12174 https://arxiv.org/pdf/2608.12174 https://arxiv.org/html/2608.12174
arXiv:2608.12174v1 Announce Type: new
Abstract: Let $\boldsymbol{X}_i=(X_{1i},X_{2i})^\top$ be independent and identically distributed observations with mean $\boldsymbol{\mu}=(\mu_1,\mu_2)^\top$ constrained by $\mu_1\leq\mu_2$. We study empirical-likelihood inference for a fixed mean vector and distinguish it from the previously known test of equality against an ordered alternative. At a fixed interior point, the constrained empirical likelihood ratio has the usual $\chi^2_2$ limit. At a fixed boundary point $(m,m)^\top$, its limit is the chi-bar-square distribution $\tfrac12\chi^2_1 \tfrac12\chi^2_2$. By contrast, profiling the unknown common mean in the equality-versus-order test yields $\tfrac12\chi^2_0 \tfrac12\chi^2_1$, the $k=2$ ordered-mean case of El Barmi (1996). We give an exact reduction of the latter statistic to the empirical likelihood of the paired differences, establish the localization step needed for the fixed-boundary expansion, and derive a local-to-boundary limit showing that interior calibration is not uniform over $n^{-1/2}$-neighborhoods of the boundary. Monte Carlo experiments under Gaussian, Student $t_5$, and shifted log-normal sampling examine fixed, boundary, and local regimes with explicit numerical-failure accounting. Illustrative paired-data analyses show the practical distinction between fixed-candidate confidence regions, directional equality tests, and ordinary scalar empirical-likelihood intervals truncated to the nonnegative parameter space.
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Replaced article(s) found for astro-ph.CO. https://arxiv.org/list/astro-ph.CO/new
[1/2]:
- Frequentist Cosmological Constraints from Full-Shape Clustering Measurements in DESI DR1
James Morawetz, et al.
https://arxiv.org/abs/2508.11811 https://mastoxiv.page/@arXiv_astrophCO_bot/115054617575953333
- Is Dark Energy Increasing or Decreasing in the Late Universe?
Maryam Aghaei Abchouyeh, Maurice H. P. M. van Putten
https://arxiv.org/abs/2509.23168 https://mastoxiv.page/@arXiv_astrophCO_bot/115292271970370289
- CMB Hemispherical Power Asymmetry from Early Phase of Inflation
Akash Gandhi, Mohit Panwar, Pankaj Jain
https://arxiv.org/abs/2509.24712 https://mastoxiv.page/@arXiv_astrophCO_bot/115292556588124095
- Cosmological Implication of Cross-correlation between Galaxy Clustering and 21-cm Line Intensity ...
Yong-Seon Song, Minji Oh, Kyungjin Ahn, Feng Shi
https://arxiv.org/abs/2512.11353 https://mastoxiv.page/@arXiv_astrophCO_bot/115722792571619796
- Core-Halo Mass Relation in Cosmological Vector Dark Matter
Jiajun Chen, Yonghao Yao, David J. E. Marsh
https://arxiv.org/abs/2607.18025 https://mastoxiv.page/@arXiv_astrophCO_bot/116957011896583949
- ZTF SN Ia DR2 follow-up: early excess in Type Ia supernova light curves
Tom\'as E. M\"uller-Bravo, et al.
https://arxiv.org/abs/2607.22050
- Validation of the DESI DR2 Ly$\alpha$ forest full-shape analysis
M. Herbold, et al.
https://arxiv.org/abs/2607.27411 https://mastoxiv.page/@arXiv_astrophCO_bot/117013522013221755
- Progenitor age-bias-corrected Type Ia supernovae favor a logarithmic luminosity-distance relation
Hoang Ky Nguyen
https://arxiv.org/abs/2608.00806 https://mastoxiv.page/@arXiv_astrophCO_bot/117036166129420866
- A refined method for measuring cosmological distances using variability and proper motions in AGN...
Hodgson, Carr, Parkinson, Statti, Myeong, L'Huillier, Shafieloo, Liodakis, Oh
https://arxiv.org/abs/2608.02202 https://mastoxiv.page/@arXiv_astrophCO_bot/117036302970516638
- Dark Baryon Black Holes
Stefano Profumo
https://arxiv.org/abs/2502.16439 https://mastoxiv.page/@arXiv_hepph_bot/114063445210577923
- Extending Weinberg's EFT: effective scalar-tensor theories up to sixth order
Eugeny Babichev, Suk\c{r}ti Bansal, Maria Mylova, Antonio Padilla
https://arxiv.org/abs/2512.13453 https://mastoxiv.page/@arXiv_hepth_bot/115728934638285022
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Single-Variable Solutions in Supergravity
W. A. Sabra, R. Slim
https://arxiv.org/abs/2608.13155 https://arxiv.org/pdf/2608.13155 https://arxiv.org/html/2608.13155
arXiv:2608.13155v1 Announce Type: new
Abstract: We construct four families of spacetime metrics depending on a single variable for a broad class of $D$-dimensional gravitational theories coupled to scalar and Abelian gauge fields. As applications of the general formalism, we derive one-variable solutions of ungauged $\mathcal{N}=2$, $D=4$ supergravity coupled to vector multiplets. We also obtain explicit solutions for a consistent truncation of $\mathcal{N}=8$, $D=4$ supergravity, as well as for theories whose scalar fields parametrize the symmetric coset manifolds $SL(N,\mathbb{R})/SO(N,\mathbb{R})$. In all cases, the geometry of the scalar manifold plays a central role in determining the structure of the resulting solutions with nontrivial scalar and gauge field configurations.
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