Lower order positivity and holomorphic operators
نویسندگان
چکیده
منابع مشابه
Non-positivity of Groenewold operators
A central feature in the Hilbert space formulation of classical mechanics is the quantisation of classical Liouville densities, leading to what may be termed term Groenewold operators. We investigate the spectra of the Groenewold operators that correspond to Gaussian and to certain uniform Liouville densities. We show that when the classical coordinatemomentum uncertainty product falls below He...
متن کاملTopological Order and Reflection Positivity
The interplay between the two fundamental concepts of topological order and reflection positivity allows one to characterize the ground states of certain many-body Hamiltonians. We define topological order in an appropriate fashion and show that certain operators have positive expectation value in all ground states. We apply our method to vortex loops in a model relevant to topological quantum ...
متن کاملNonstandard explicit third-order Runge-Kutta method with positivity property
When one solves differential equations, modeling physical phenomena, it is of great importance to take physical constraints into account. More precisely, numerical schemes have to be designed such that discrete solutions satisfy the same constraints as exact solutions. Based on general theory for positivity, with an explicit third-order Runge-Kutta method (we will refer to it as RK3 method) pos...
متن کاملLower Bounds and Positivity Conditions for Green’s Functions to Second Order Differential-Delay Equations
We consider the Cauchy problem on the positive half-line for the differential-delay equation ü(t) + 2c0(t)u̇(t) + c1(t)u̇(t − h) + d0(t)u(t) + d1(t)u(t − h) + d2(t)u(t − 2h) = 0 where ck(t), dj(t) (t ≥ 0; k = 0, 1; j = 0, 1, 2) are continuous functions. Conditions providing the positivity of the Green function and a lower bound for that function are derived. Our results are new even in the case o...
متن کاملImplicit Positivity-preserving High Order
Positivity-preserving discontinuous Galerkin (DG) methods for solving hyperbolic 5 conservation laws have been extensively studied in the last several years. But nearly all the devel6 oped schemes are coupled with explicit time discretizations. Explicit discretizations suffer from the 7 constraint for the Courant-Friedrichs-Levis (CFL) number. This makes explicit methods impractical 8 for probl...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Functional Analysis
سال: 1984
ISSN: 0022-1236
DOI: 10.1016/0022-1236(84)90023-5