In the presence of appropriate non-minimal couplings between a scalar field and curvature squared Gauss–Bonnet (GB) term, compact objects such as neutron stars black holes (BHs) can spontaneously scalarize, becoming preferred vacuum. Such strong gravity phase transitions have attracted considerable attention recently. The coupling functions that allow this mechanism are, however, always postula...

Abstract In engineering applications one often has to trade-off among several objectives as, for example, the mechanical stability of a component, its efficiency, weight and cost. We consider biobjective shape optimization problem maximizing ceramic component under tensile load while minimizing volume. Stability is thereby modeled using Weibull-type formulation probability failure external load...

Abstract We study the approximation of general multiobjective optimization problems with help scalarizations. Existing results state that minimization can be approximated well by norm-based However, for maximization problems, only impossibility are known so far. Countering this, we show all can, in principle, equally In this context, introduce a transformation theory scalarizations establishes ...

In managerial and economic applications, there appear problems in which the goal is to simultaneously optimize several criteria functions (CFs). However, since the CFs are in conflict with each other in such cases, there is not a feasible point available at which all CFs could be optimized simultaneously. Thus, in such cases, a set of points, referred to as 'non-dominate' points (NDPs), will be...

We investigate the tachyonic instability of Kerr-Newman (KN) black holes in Einstein-Maxwell-scalar (EMS) theory with a positive coupling parameter $\ensuremath{\alpha}$. This corresponds to exploring onset spontaneous scalarization for KN holes. For this purpose, we use hyperboloidal foliation method solve linearized scalar equation numerically. obtain 3D graph [${\mathrm{log}}_{10}\ensuremath...

Abstract This work deals with the efficient numerical characterization of Pareto stationary fronts for multiobjective optimal control problems a moderate number cost functionals and mildly nonsmooth, elliptic, semilinear PDE-constraint. When “ample” controls are considered, strong stationarity conditions that can be used to numerically characterize known our problem. We show finite dimensional ...

Black hole spontaneous scalarization has been attracting more and attention as it circumvents the well-known no-hair theorems. In this work, we study in Einstein-scalar-Gauss-Bonnet theory with a probe scalar field black background different curvatures. We first signal of positive curvature spacetimes. The AdS spacetime could be formed easier than that flat case. Then, investigate around holes ...

In this research, some of the issues that arise from scalarization multi-objective optimization problem in Advantage Actor Critic (A2C) reinforcement learning algorithm are investigated. The paper shows how a naive can lead to gradients overlapping. Furthermore, possibility entropy regularization term be source uncontrolled noise is discussed. With respect above issues, technique avoid gradient...

We present the first fully nonlinear study on accretion of scalar fields onto a seed black hole in anti--de Sitter spacetime Einstein-Maxwell-scalar theory. Intrinsic critical phenomena dynamical transition between bald and scalarized holes are disclosed. In scalarizations, is discontinuous metastable acts as an attractor at threshold. construct new physical mechanism to dynamically descalarize...