Related Experiment Video
Updated: Jul 2, 2025

Characterization of Thermal Transport in One-dimensional Solid Materials
Published on: January 26, 2014
Partial Ly thermalization in an analytic nonlinear diffusion model
1Institute for Theoretical Physics, Heidelberg University, Philosophenweg 16, Heidelberg, 69120, Baden Württemberg, Germany. wolschin@uni-hd.de.
Abstract:
During recombination, the cosmic background radiation is disturbed, in particular, by Lyman-alpha emissions from neutral hydrogen. It is proposed to account for the subsequent time-dependent partial thermalization of the Ly energy content in an analytically solvable nonlinear diffusion model. The amplitude of the partially thermalized and redshifted Ly line is found to be too low to be visible in the cosmic microwave spectrum, in accordance with previous numerical models and Planck observations.
Related Concept Videos
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length,...
Poisson's And Laplace's Equation
Le Chatelier's Principle: Changing Temperature
To understand this phenomenon, consider the elementary reaction:
Linear time-invariant Systems
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be...
Joule-Thomson Effect
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...

