* Correspondence: [email protected] Department of Mathematics and Computer Science, Amirkabir University of Technology, Hafez Ave., P.O. Box 15875-4413, Tehran, Iran Abstract In this paper, a CAT(0) version of famous Fan’s minimax inequality is established and as its application, we obtain some fixed point theorems and best approximation theorems in CAT(0) spaces. 2000 Mathematics Subject Classifi...

Abstract This note presents an estimator of the hazard rate function based on right censored data. A collection of estimators is built from a regression-type contrast, in a general collection of linear models. Then, a penalised model selection procedure provides an estimator which satisfies an oracle inequality. In particular, we can prove that it is adaptive in the minimax sense on Hölder spaces.

In this paper, we obtain several new generalized KKM-type theorems under a new coercivity condition and the condition of intersectionally closedness which improves condition of transfer closedness. As applications, we obtain new versions of equilibrium problem, minimax inequality, coincidence theorem, fixed point theorem and an existence theorem for an 1-person game.

We consider the problem of combining a (possibly uncountably infinite) set of affine estimators in non-parametric regression model with heteroscedastic Gaussian noise. Focusing on the exponentially weighted aggregate, we prove a PAC-Bayesian type inequality that leads to sharp oracle inequalities in discrete but also in continuous settings. The framework is general enough to cover the combinati...

Classical approaches to location problems are based on the minimization of the average distance (the median concept) or the minimization of the maximum distance (the center concept) to the service facilities. The median solution concept is primarily concerned with the spatial efficiency while the center concept is focused on the spatial equity. The k-centrum model unifies both the concepts by m...

We use a laboratory experiment to examine whether and to what extent other-regarding preferences (efficiency, inequality aversion and maximin concerns) of team managers influence their management style in choice under risk. We find that managers who prefer efficiency are more likely to exercise an autocratic management style by ignoring preferences of their team members. Equality concerns have ...

Abstract An existence result for a generalized inequality over possible unbounded domain in finite-dimensional space is established. The proof technique allows to avoid any monotonicity assumption. We adapt weak coercivity condition introduced Castellani and Giuli (J Glob Optim 75:163–176, 2019) game which extends an older one proposed by Konnov Dyabilkin 49:575–577, 2011) equilibrium problems....