Latest Posts

  • Splitting Schemes

    Consider the differential equation with phase state $M$

  • Splitting Schemes

    Consider the differential equation with phase state $M$

  • Exponential Integrators

  • Hypothesis Testing

    What is the difference between Hypothesis Testing and Classification?

  • Shapley Value

    Economical Ideas.

  • Random Matrix

    Let us first recall some classical result on random matrix.

  • Geometry of Markov Chains

    Mixing.

  • Dyson Series

    Some quantum mechanical calculation.

  • Watermarks for LLM

    Statistical watermark leverage the psuedorandomness during decoding.

  • Convex Optimization

    Consider the general constrained optimization problem (P) shown below, where we have not assumed anything regarding the functions $f$, $h$, $l$ (like convexity).

  • Stability of Lindblad's Equation

    Under certain conditions the evolution of a quantum system interacting with its environment can be described by a quantum dynamical semigroup and shown to satisfy a Lindblad master equation

  • Boolean Analysis

    Denote

  • Traditional Machine Learning Theory

    metric entropy, chaining…

  • Matrix Game

    RLHF (Reinforcement Learning from Human Feedback) has been the dominant technique to align an intelligent agent to human preferences.

  • Continuous Regret Analysis

    lexing’s paper

  • Lyapunov Functions

    How to derive an estimate better than Gronwall’s inequality?

  • Hypocoercivity

    Hypocoercivity is a mathematical concept used to describe the behavior of certain dynamical systems and partial differential equations (PDEs) that do not exhibit traditional coercivity properties but still exhibit convergence to equilibrium over time. In the study of kinetic equations and systems where traditional coercive methods (like those used in parabolic PDEs) do not apply, we may resort to hypocoercivity.

  • Deriving the Asymptotics

    Deriving the asymptotics

  • Estimation of Heavy Tails

    In this article, I breifly introduce some current methods of estimating the tail of a heavy tail distributions.

  • The Spectral Representation of a Stationary Prcoess

    The spectral representation of a stationary process ${X_t}$ essentially decomposes ${X_t}$ into a sum of sinusoidal components with uncorrelated random coefficients. This is an analogue of the more familiar Fourier representation of deterministic functions.

  • Le Cam Methods

    In this article, I breifly explain the idea of Le Cam methods.

  • Double Machine Learning

    In this article, I breifly explain the idea of double machine learning.

  • Koopman Operator

    In this article, I breifly explain the theory of Koopman Operator.

  • Point Estimation

    In this article, I breifly review the theory of point estimation.

  • Classical Gradient Descent Analysis

    In this article, I recap the classical gradient descent analysis.

  • NTK

    In this article, we explain the Neural Tangent Kernel.

  • PAC Bayesian

    In this article, we explain the PAC-Bayesian generalization bound.

  • Quantum Computing

    In this article, we first recall the basic postulates of quantum computing. Then we mainly focus on the mathematical structures behind it.

  • Feature Learning

    One notable difference between traditional machine learning algorithms and deep learning is that in deep learning, the features are learnable and can be interpreted.

  • Symmetry in Deep Learning Theory

    We can leverage symmetry.

  • Completely Positive Map

    In this article, I describe $C^*$-algebra, complete positive map, and its relationship to quantum mechanics.

  • Circuit Complexity

    Circuit complexity is a measure of how hard it is to express or compute a boolean function.

  • Communication Complexity

    Communication complexity was first introduced by Andrew Yao in 1973, while studying the problem of computation distributed among several machines.

  • Diffusion Models

    Let us first recall how to reverse a classical diffusion process.

  • Great Researchers

    In this series I try to imagine and examine the great figures in the history as researchers. The goal is not to diefy anyone, but to examine great figures in the history and to inspire researchers today.

  • Unlocking the Essential Characteristics of Doing Research

    This is how I understand research.

  • Investigation in Plane Geometry

    This article records some of my proofs in plane geometry.

  • New Geometry Problems

    This article records some problems in plane geometry that I, my friend Yonggang Ren, and my middle school teacher Lingfeng Chen have discovered.

  • An IMO Problem Revisited

    This article records some solutions of a problem in plane geometry that I discovered.