Tootfinder

Testing Coasting Cosmologies with Large-Scale Structure Growth
D\'avid A. K\"odm\"on, P\'eter Raffai
https://arxiv.org/abs/2506.11826 htt…

Testing Coasting Cosmologies with Large-Scale Structure Growth
We derive analytical expressions for the growth factor, $D(z)$, and density-weighted growth rate, $fσ_8(z)$, for coasting cosmologies, in which the scale factor is a linear function of time. We fit the latter to data from redshift space distortion measurements in the redshift range $z<2$ using the \texttt{dynesty} implementation of a nested sampling algorithm. In total, four models are tested: three coasting models with curvature parameters ${k=\{-1, 0, +1\}}$ in $H^2_0c^{-2}$ units, as well a…

Measurement of $\psi(2S)$ to $J/\psi$ cross-section ratio as function of multiplicity in $p$Pb collisions at$\sqrt{s_{NN}} = 8.16$ TeV
LHCb collaboration, et al.
https://arxiv.org/abs/2506.08624

Measurement of $ψ(2S)$ to $J/ψ$ cross-section ratio as function of multiplicity in $p$Pb collisions at$\sqrt{s_{NN}} = 8.16$ TeV
The production ratio of $ψ(2S)$ to $J/ψ$ charmonium states is presented as a function of multiplicity in proton-lead collisions at a centre-of-mass energy of $\sqrt{s_{NN}}=8.16$ TeV, for both prompt and nonprompt sources. The total luminosity recorded by the LHCb experiment corresponds to 13.6 $pb^{-1}$ for $p$Pb collisions and 20.8 $pb^{-1}$ for Pb$p$ collisions, where the first particle indicates the forward direction of the detector. Measurements are performed in the dimuon final state at…

Unrolling Nonconvex Graph Total Variation for Image Denoising
Songlin Wei, Gene Cheung, Fei Chen, Ivan Selesnick
https://arxiv.org/abs/2506.02381 https://

Unrolling Nonconvex Graph Total Variation for Image Denoising
Conventional model-based image denoising optimizations employ convex regularization terms, such as total variation (TV) that convexifies the $\ell_0$-norm to promote sparse signal representation. Instead, we propose a new non-convex total variation term in a graph setting (NC-GTV), such that when combined with an $\ell_2$-norm fidelity term for denoising, leads to a convex objective with no extraneous local minima. We define NC-GTV using a new graph variant of the Huber function, interpretable …

Wave-function microscopy: Derivation and anatomy of exact algebraic spinful wave functions and full Wigner-molecular spectra of a few highly correlated rapidly rotating ultracold fermionic atoms
Constantine Yannouleas, Uzi Landman
https://arxiv.org/abs/2506.08145

Wave-function microscopy: Derivation and anatomy of exact algebraic spinful wave functions and full Wigner-molecular spectra of a few highly correlated rapidly rotating ultracold fermionic atoms
Exploring strongly correlated spinful states of few fermionic ultracold atoms in a rapidly rotating trap, an example of which was recently realized for two fermionic $^6$Li atoms in an optical tweezer, we derive analytical (algebraic) total-spin-eigenstate wavefunctions through the development and employment of a theoretical platform that integrates exact numerical diagonalization (full configuration interaction, FCI) with symbolic language processing. For such rapid rotations, where the atoms …

This https://arxiv.org/abs/2502.10613 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Function recovery and optimal sampling in the presence of nonuniform evaluation costs
We consider recovering a function $f : D \rightarrow \mathbb{C}$ in an $n$-dimensional linear subspace $\mathcal{P}$ from i.i.d. pointwise samples via (weighted) least-squares estimators. Different from most works, we assume the cost of evaluating $f$ is potentially nonuniform, and governed by a cost function $c : D \rightarrow (0,\infty)$ which may blow up at certain points. We therefore strive to choose the sampling measure in a way that minimizes the expected total cost. We provide a recover…

Packing tetrahedrons in edge-weighted graphs
Wanting Sun, Shunan Wei, Donglei Yang
https://arxiv.org/abs/2506.07147 https://arxiv.org…

Packing tetrahedrons in edge-weighted graphs
We prove that for all $μ>0, t\in (0,1)$ and sufficiently large $n\in 4\mathbb{N}$, if $G$ is an edge-weighted complete graph on $n$ vertices with a weight function $w: E(G)\rightarrow [0,1]$ and the minimum weighted degree $δ^w(G)\geq (\tfrac{1+3t}{4}+μ)n$, then $G$ contains a $K_4$-factor where each copy of $K_4$ has total weight more than $6t$. This confirms a conjecture of Balogh--Kemkes--Lee--Young for the tetrahedron case.

This https://arxiv.org/abs/2506.04665 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_csGT_…

An O(log log n)-approximate budget feasible mechanism for subadditive valuations
In budget-feasible mechanism design, there is a set of items $U$, each owned by a distinct seller. The seller of item $e$ incurs a private cost $\overline{c}_e$ for supplying her item. A buyer wishes to procure a set of items from the sellers of maximum value, where the value of a set $S\subseteq U$ of items is given by a valuation function $v:2^U\to \mathbb{R}_+$. The buyer has a budget of $B \in \mathbb{R}_+$ for the total payments made to the sellers. We wish to design a mechanism that is tr…

On the domains of first order differential operators on the Sierpi\'{n}ski gasket
Waldemar Schefer
https://arxiv.org/abs/2506.08679 https://

On the domains of first order differential operators on the Sierpiński gasket
We study the first order structure of $L^2$-differential one-forms on the Sierpiński gasket. We consider piecewise energy finite functions related to one-forms, normal parts, and show self-similarity properties of one-forms as in the case of energy finite functions on the Sierpiński gasket. We introduce first order differential operators, taking functions into functions, that can be understood as total derivatives with respect to some reference function or form. The main result is a pointwise…

Density dependent embedding potentials for piecewise exact densities
Tomasz Adam Wesolowski
https://arxiv.org/abs/2506.08744 https://…

Density dependent embedding potentials for piecewise exact densities
Frozen Density Embedding Theory (FDET) [Wesolowski {\it Phys. Rev. A} {\bf 77}, 012504 (2008)] provides the interpretation of the eigenvalue equations for an embedded $N'$-electron wavefunction, in which the embedding operator is multiplicative, as the Euler-Lagrange equation corresponding to the constrained minimisation of the Hohenberg-Kohn energy functional. The constraint is given by a non-negative function integrating to an integer $N-N'>0$ with $N$ being the total number of electrons in t…

Neural Networks for Parameter Estimation of the Discretely Observed Hawkes Process
Jason J. Lambe, Feng Chen, Tom Stindl, Tsz-Kit Jeffrey Kwan
https://arxiv.org/abs/2506.01258

Neural Networks for Parameter Estimation of the Discretely Observed Hawkes Process
When the sample path of a Hawkes process is observed discretely, such that only the total event counts in disjoint time intervals are known, the likelihood function becomes intractable. To overcome the challenge of likelihood-based inference in this setting, we propose to use a likelihood-free approach to parameter estimation, where a fully connected neural network (NN) is trained using simulated data to estimate the parameters of the Hawkes process from a summary statistic of the count data. A…

This https://arxiv.org/abs/2407.14441 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

A normalized gradient flow method for computing ground states of spin-2 Bose-Einstein condensates
We propose and analyze an efficient and accurate numerical method for computing ground states of spin-2 Bose-Einstein condensates (BECs) by using the normalized gradient flow (NGF). In order to successfully extend the NGF to spin-2 BECs which has five components in the vector wave function but with only two physical constraints on total mass conservation and magnetization conservation, two important techniques are introduced for designing the proposed numerical method. The first one is to syste…

On the motion of a point charge in a plate capacitor considering influence effects
Heinz-J\"urgen Schmidt, Thomas Br\"ocker
https://arxiv.org/abs/2506.06132

On the motion of a point charge in a plate capacitor considering influence effects
A point charge between the plates of a capacitor generates an influence charge distribution on the plates that modify the electric field acting upon the point charge. This effect is described by the well-known Dirichlet Green's function for the two parallel conducting plate problem for which we derive an infinite mirror charge series representation. At the line perpendicular to the plates and passing through the point charge this Green's function and hence the total force can be explicitly eval…

An O(log log n)-approximate budget feasible mechanism for subadditive valuations
Rian Neogi, Kanstantsin Pashkovich, Chaitanya Swamy
https://arxiv.org/abs/2506.04665

An O(log log n)-approximate budget feasible mechanism for subadditive valuations
In budget-feasible mechanism design, there is a set of items $U$, each owned by a distinct seller. The seller of item $e$ incurs a private cost $\overline{c}_e$ for supplying her item. A buyer wishes to procure a set of items from the sellers of maximum value, where the value of a set $S\subseteq U$ of items is given by a valuation function $v:2^U\to \mathbb{R}_+$. The buyer has a budget of $B \in \mathbb{R}_+$ for the total payments made to the sellers. We wish to design a mechanism that is tr…

On the entropy of the massive conformal gravity universe
F. F. Faria
https://arxiv.org/abs/2505.17171 https://arxiv.org/pdf/2505.1717…

On the entropy of the massive conformal gravity universe
We find that the total entropy of the massive conformal gravity universe is an increasing function of time, and therefore the cosmological model of the theory passes the generalized second law of thermodynamics test.