The nonlocal isoperimetric problem for polygons: Hardy–Littlewood and Riesz inequalities

The Poincaré Metric and Isoperimetric Inequalities for Hyperbolic Polygons

We prove several isoperimetric inequalities for the conformal radius (or equivalently for the Poincaré density) of polygons on the hyperbolic plane. Our results include, as limit cases, the isoperimetric inequality for the conformal radius of Euclidean n-gons conjectured by G. Pólya and G. Szegö in 1951 and a similar inequality for the hyperbolic n-gons of the maximal hyperbolic area conjecture...

Isoperimetric Inequalities for a Nonlinear Eigenvalue Problem

An estimate for the spectrum of the two-dimensional eigenvalue problem Am + Xe" = 0 in D (X > 0), u = 0 on 3 D is derived, and upper and lower pointwise bounds for the solutions are constructed. 1. Let D be a simply connected bounded domain in the plane with a piecewise analytic boundary 3D. Consider the nonlinear Dirichlet problem Am(x) + Xe"w = 0 in D, (1) u(x) = 0 on dD, where X is a positiv...

the algorithm for solving the inverse numerical range problem

برد عددی ماتریس مربعی a را با w(a) نشان داده و به این صورت تعریف می کنیم w(a)={x8ax:x ?s1} ، که در آن s1 گوی واحد است. در سال 2009، راسل کاردن مساله برد عددی معکوس را به این صورت مطرح کرده است : برای نقطه z?w(a)، بردار x?s1 را به گونه ای می یابیم که z=x*ax، در این پایان نامه ، الگوریتمی برای حل مساله برد عددی معکوس ارانه می دهیم.

Enumerating isodiametric and isoperimetric polygons

For a positive integer n that is not a power of 2, precisely the same family of convex polygons with n sides is optimal in three different geometric problems. These polygons have maximal perimeter relative to their diameter, maximal width relative to their diameter, and maximal width relative to their perimeter. We study the number of different convex n-gons E(n) that are extremal in these thre...

Isoperimetric Inequalities and Eigenvalues