Results 71 to 80 of about 71,699 (272)
Degree theory for 4‐dimensional asymptotically conical gradient expanding solitons
Communications on Pure and Applied Mathematics, EarlyView.Abstract We develop a new degree theory for 4‐dimensional, asymptotically conical gradient expanding solitons. Our theory implies the existence of gradient expanding solitons that are asymptotic to any given cone over S3$S^3$ with non‐negative scalar curvature. We also obtain a similar existence result for cones whose link is diffeomorphic to S3/Γ$S^3/\
Richard H. Bamler, Eric Chen
wiley +1 more source
Support-based lower bounds for the positive semidefinite rank of a nonnegative matrix [PDF]
, 2013 The positive semidefinite rank of a nonnegative $(m\times n)$-matrix~$S$ is the minimum number~$q$ such that there exist positive semidefinite $(q\times q)$-matrices $A_1,\dots,A_m$, $B_1,\dots,B_n$ such that $S(k,\ell) = \mbox{tr}(A_k^* B_\ell)$.
Dirk, Oliver Theis, Troy Lee
core
, 2012 We consider a short rate model, driven by a stochastic process on the cone of positive semidefinite matrices.
ALESSANDRO GNOATTO +4 more
core +1 more source
Pick matrix conditions for sign-definite solutions of the algebraic Riccati equation [PDF]
, 2001 We study the existence of positive and negative semidefinite solutions of algebraic Riccati equations (ARE) corresponding to linear quadratic problems with an indefinite cost functional.
Rapisarda, Paolo, Trentelman, Harry L.
core +2 more sources
Uncertain Short‐Run Restrictions and Statistically Identified Structural Vector Autoregressions
Journal of Applied Econometrics, EarlyView.ABSTRACT This study proposes a combination of a statistical identification approach with potentially invalid short‐run zero restrictions. The estimator shrinks towards imposed restrictions and stops shrinkage when the data provide evidence against a restriction.
Sascha A. Keweloh, Shu Wang
wiley +1 more source
Heinz均值凸性的一个注记(A note on the convexity of the Heinz means)
Zhejiang Daxue xuebao. Lixue ban, 2013 Recently, KITTANEH obtained an improvement of the Heinz inequality for all unitarily invariant norms. In this note, we obtain a refinement of KITTANEH's result. We shall conclude this paper with some numerical examples.
ZOULi-min(邹黎敏)
doaj +1 more source
A Stochastic Approach to Quantifying the Propagation of Uncertainty in Soil Organic Carbon Content
Journal of Plant Nutrition and Soil Science, EarlyView.ABSTRACT Background Precision agriculture (PA) is a site‐specific management approach that utilises spatiotemporal information to improve productivity while also promoting sustainability. Accurate estimates of soil properties, along with the uncertainty of these estimates, are necessary for decision‐making in PA.
Leonardo Inforsato +6 more
wiley +1 more source
Products of positive semidefinite matrices
Linear Algebra and its Applications, 1988 The author proves that a matrix T is the product of finitely many nonnegative matrices if and only if det(T)\(\geq 0\) and in this case, five such matrices are sufficient.
openaire +1 more source
On the Mean‐Field Limit of Consensus‐Based Methods
Mathematical Methods in the Applied Sciences, EarlyView.ABSTRACT Consensus‐based optimization (CBO) employs a swarm of particles evolving as a system of stochastic differential equations (SDEs). Recently, it has been adapted to yield a derivative free sampling method referred to as consensus‐based sampling (CBS). In this paper, we investigate the “mean‐field limit” of a class of consensus methods, including
Marvin Koß, Simon Weissmann, Jakob Zech
wiley +1 more source
Generalized Randić Estrada Indices of Graphs
Mathematics, 2022 Let G be a simple undirected graph on n vertices. V. Nikiforov studied hybrids of AG and DG and defined the matrix AαG for every real α∈[0,1] as AαG=αDG+(1−α)AG.
Eber Lenes +3 more
doaj +1 more source