论文标题
用于模拟多项式微分方程的有效量子算法
An efficient quantum algorithm for simulating polynomial differential equations
论文作者
论文摘要
我们提出了一种有效的量子算法,以模拟量子平台上任意度的多项式矢量场模拟非线性微分方程。由于高维度,刚度,非线性和敏感的依赖性,在经典计算机上求解由普通微分方程(OD)或部分微分方程(PDE)控制的物理系统模型可能具有挑战性。对于稀疏的$ n $维线性ODE,已经开发了量子算法,该算法可以使用量子线性系统算法(QLSA)在poly(log(log(nx))时间中产生与溶液成比例的量子状态。最近,通过应用卡尔曼线性化,将该框架扩展到具有二次多项式矢量场的非线性ODES系统,从而使二次系统嵌入到近似线性形式中。进行了详细的复杂性分析,该分析在某些条件下显示出显着的计算优势。我们提出了该算法的扩展,以处理$ k $ thger的多项式矢量字段的非线性ODES系统,以任意(有限)值为$ K $。步骤涉及:1)将$ k $的多项式选映射到较高的二维多项式颂歌; 2)应用Carleman线性化将二次颂歌转换为线性ODE的无限二维系统; 3)使用正向Euler方法和QLSA截断和离散线性颂歌并求解。另外,可以将Carleman线性化直接应用于$ K $ TEGRY ode,从而产生无限维线性ODES系统,然后应用步骤3。该解决方案可以在计算上更有效。我们介绍了所提出的算法的详细复杂性分析,证明了$ k $上的运行时的多项式缩放,并在示例中演示了框架。
We present an efficient quantum algorithm to simulate nonlinear differential equations with polynomial vector fields of arbitrary degree on quantum platforms. Models of physical systems that are governed by ordinary differential equations (ODEs) or partial differential equation (PDEs) can be challenging to solve on classical computers due to high dimensionality, stiffness, nonlinearities, and sensitive dependence to initial conditions. For sparse $n$-dimensional linear ODEs, quantum algorithms have been developed which can produce a quantum state proportional to the solution in poly(log(nx)) time using the quantum linear systems algorithm (QLSA). Recently, this framework was extended to systems of nonlinear ODEs with quadratic polynomial vector fields by applying Carleman linearization that enables the embedding of the quadratic system into an approximate linear form. A detailed complexity analysis was conducted which showed significant computational advantage under certain conditions. We present an extension of this algorithm to deal with systems of nonlinear ODEs with $k$-th degree polynomial vector fields for arbitrary (finite) values of $k$. The steps involve: 1) mapping the $k$-th degree polynomial ODE to a higher dimensional quadratic polynomial ODE; 2) applying Carleman linearization to transform the quadratic ODE to an infinite-dimensional system of linear ODEs; 3) truncating and discretizing the linear ODE and solving using the forward Euler method and QLSA. Alternatively, one could apply Carleman linearization directly to the $k$-th degree polynomial ODE, resulting in a system of infinite-dimensional linear ODEs, and then apply step 3. This solution route can be computationally more efficient. We present detailed complexity analysis of the proposed algorithms, prove polynomial scaling of runtime on $k$ and demonstrate the framework on an example.