Regularity of minimizers for second order variational problems in one independent variable

2011 ◽  
Vol 29 (2) ◽  
pp. 547-557
Author(s):  
Christos Gavriel ◽  
◽  
Richard Vinter
OPSEARCH ◽  
2014 ◽  
Vol 52 (3) ◽  
pp. 582-596 ◽  
Author(s):  
Anurag Jayswal ◽  
I. M. Stancu-Minasian ◽  
Sarita Choudhury

A class of second-order linear differential equations with a large parameter u is considered. It is shown that Liouville–Green type expansions for solutions can be expressed using factorial series in the parameter, and that such expansions converge for Re ( u ) > 0, uniformly for the independent variable lying in a certain subdomain of the domain of asymptotic validity. The theory is then applied to obtain convergent expansions for modified Bessel functions of large order.


2020 ◽  
Vol 13 (2) ◽  
pp. 115-140 ◽  
Author(s):  
Nikos Katzourakis ◽  
Tristan Pryer

AbstractIn this paper we initiate the study of second-order variational problems in {L^{\infty}}, seeking to minimise the {L^{\infty}} norm of a function of the hessian. We also derive and study the respective PDE arising as the analogue of the Euler–Lagrange equation. Given {\mathrm{H}\in C^{1}(\mathbb{R}^{n\times n}_{s})}, for the functional\mathrm{E}_{\infty}(u,\mathcal{O})=\|\mathrm{H}(\mathrm{D}^{2}u)\|_{L^{\infty}% (\mathcal{O})},\quad u\in W^{2,\infty}(\Omega),\mathcal{O}\subseteq\Omega,{}the associated equation is the fully nonlinear third-order PDE\mathrm{A}^{2}_{\infty}u:=(\mathrm{H}_{X}(\mathrm{D}^{2}u))^{\otimes 3}:(% \mathrm{D}^{3}u)^{\otimes 2}=0.{}Special cases arise when {\mathrm{H}} is the Euclidean length of either the full hessian or of the Laplacian, leading to the {\infty}-polylaplacian and the {\infty}-bilaplacian respectively. We establish several results for (1) and (2), including existence of minimisers, of absolute minimisers and of “critical point” generalised solutions, proving also variational characterisations and uniqueness. We also construct explicit generalised solutions and perform numerical experiments.


1955 ◽  
Vol 51 (4) ◽  
pp. 604-613
Author(s):  
Chike Obi

1·1. A general problem in the theory of non-linear differential equations of the second order is: Given a non-linear differential equation of the second order uniformly almost periodic (u.a.p.) in the independent variable and with certain disposable constants (parameters), to find: (i) the non-trivial relations between these parameters such that the given differential equation has a non-periodic u.a.p. solution; (ii) the number of periodic and non-periodic u.a.p. solutions which correspond to each such relation; and (iii) explicit analytical expressions for the u.a.p. solutions when they exist.


1964 ◽  
Vol 86 (2) ◽  
pp. 111-116 ◽  
Author(s):  
S. M. Wu

This paper is a continuation of a previous paper in which the basic philosophy of response surface methodology has been explained and a first-order tool-life-predicting equation has been developed. This part of the paper illustrates the development of a second-order tool-life-predicting equation in 18 and 24 tests. It was found that the second-order effect did not show statistical significance within the cutting ranges of this project; however, the second-order effect of cutting speed has been found important by the study of residuals. If only one independent variable is investigated, a minimal number of tests can be used to find a second-order equation. Examples of designs in three, five, and six tests are illustrated.


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