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Energy Manifold Natural Gradient Descent: From Riemannian Optimization to Modern Neuroscience, NeuroAI and Quantum Physics

Dr. Rishabh Pathak
When Geometry, Energy, Artificial Intelligence and Neuroscience Converge Modern Artificial Intelligence is rapidly moving beyond the idea that learning simply means minimizing an error function. Increasingly, researchers are asking a deeper question: what is the structure of the space in which learning takes place? This question becomes particularly important when the system being modelled is constrained, nonlinear, dynamic, or governed by physical principles. A recent work titled “Energy Manifold Natural Gradient Descent: Riemannian Optimization for Neural PDE Solvers” , by Zhangyong Liang and Huanhuan Gao, introduces Energy Manifold Natural Gradient Descent (EMNGD) , a mathematical framework that extends energy-based natural-gradient optimization from unconstrained Euclidean parameter spaces to constrained Riemannian parameter manifolds . At its core, the framework proposes a simple but powerful principle: An optimization algorithm should not only determine how to reduce error; it sh...
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Analytical Model

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Dr. Rishabh Pathak

The analytical model used in the study of brain development focuses on estimating critical conditions at the onset of folding in the brain's surface morphology. This model is based on the Föppl–von Kármán theory and the classical fourth-order plate equation to approximate cortical folding as the instability problem of a confined, layered medium subjected to growth-induced compression.

Key aspects of the analytical model include:

1.   Föppl–von Kármán Theory: This theory provides the framework for analyzing the behavior of the brain tissue during the folding process. It helps in deriving analytical estimates for critical parameters such as the critical time, pressure, and wavelength at the onset of folding.

2.    Plate Equation: The classical fourth-order plate equation is utilized to model the cortical deflection, taking into account parameters such as cortical thickness, stiffness, growth, and external loading. This equation forms the basis for understanding the mechanical response of the brain tissue during folding.

3.   Estimation of Critical Conditions: The analytical model aims to provide quick insights into the critical conditions that trigger folding in the brain. By estimating parameters such as critical pressure and wavelength, researchers can understand the fundamental mechanisms driving cortical folding.

4.     Limitations: While the analytical model is valuable for initial estimations, it may not fully capture the evolution of complex instability patterns in the post-critical regime. This limitation highlights the need for complementary computational models to predict more realistic surface morphologies beyond the onset of folding.

In summary, the analytical model based on the Föppl–von Kármán theory serves as a foundational tool for estimating critical conditions at the onset of cortical folding in the brain. It provides valuable insights into the mechanical aspects of brain development and sets the stage for further computational modeling to explore the complexities of brain surface morphologies.

 

 

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