We construct an explicit solution of the Cauchy initial value problem for certain diffusion-type equations with variable coefficients on the entire real line. The corresponding Green function (heat kernel) is given in terms of elementary functions and certain integrals involving a characteristic function, which should be found as an analytic or numerical solution of the second order linear differential equation with time-dependent coefficients. Some special and limiting cases are outlined. Solution of the corresponding non-homogeneous equation is also found.
The Sturm-Liouville equation represents the linearized form of the first-order Riccati equation. This provides an evidence for the connection between Schwarzian derivative and this first-order nonlinear differential equation. Similar connection is not obvious for higher-order equations in the Riccati chain because the corresponding linear equations are of order greater than two. With special attention to the second- and third-order Riccati equations we demonstrate that Schwarzian derivative has a natural space in higher Riccati equations. There exist higher-order analogues of the Schwarztan de…
We report a solution of the inverse Lagrangian problem for the first order Riccati differential equation by means of an analogy with the Friedmann equation of a suitable Friedmann-Lemaître-Robertson-Walker universe in general relativity. This analogous universe has fine-tuned parameters and is unphysical, but it suggests a Lagrangian and a Hamiltonian for the Riccati equation and for the many physical systems described by it.
Shifted Riccati Procedure: Application to Conformal Barotropic FRW Cosmologies
在正压FRW宇宙学的情况下,共形时间的哈勃参数是一个简单的常系数Riccati方程的解。我们认为这些宇宙学的框架内的非相对论性超对称性,已在该地区的超对称量子力学的有效。回顾Faraoni [Amer. J. Phys. 67(1999),732-734]提出了如何将正压FRW微分方程组简化为简谐振子微分方程,我们将后者的方程组用超对称方法求解,并将其解分为两类“玻色子”(非奇异)和“费米子”(奇异)宇宙学零模解。费米子方程可以被认为是代表Stephani类型的宇宙学,即,在保形时间内,曲率变化。接下来,我们通过在这些超对称伙伴宇宙学的共同Riccati解中引入一个常数加性参数(用S表示)来应用所谓的移位Riccati过程。这导致正压Stephani宇宙学与周期性奇点在其空间曲率指数,我们称之为U和V宇宙学,第一个是玻色子型和费米子型后者。我们完全解决这些循环奇异宇宙学在其零模式的水平上,表明一个可接受的移位参数应该是纯粹的虚的,这反过来又引入了宇称时间(PT)属性的合作伙伴曲率指数。
Near-Optimal Quantum Algorithm and Complexity Analysis for Riccati Problems
Tsinghua University(清华大学);TraverseQuantum Co., Ltd.(TraverseQuantum有限公司);Yau Mathematical Sciences Center, Tsinghua University(清华大学丘成桐数学科学中心);Qiuzhen College, Tsinghua University(清华大学邱士泽学院);Institute for AI Industry Research (AIR), Tsinghua University(清华大学人工智能产业研究院);Academy of Mathematics and Systems Science, Chinese Academy of Sciences(中国科学院数学与系统科学研究院);Institute for Applied Mathematics, Tsinghua University(清华大学应用数学中心);Beijing Institute of Mathematical Sciences and Applications(北京国际数学研究中心);Department of Computer Science and Technology, Tsinghua University(清华大学计算机科学与技术系)