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guest1234
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Quick question: what is meant by thermalization of photons? And how could this effect distort CMB spectrum (anisotropies)?
Any references are also welcome.
Any references are also welcome.
The cooling of electrons and the corresponding spectral distortions are easy to calculate and only depend on the standard cosmological parameters, such as baryon to photon number density [itex]\frac{n_B}{n_\gamma}[/itex] [...]
guest1234 said:Thanks, your answers cleared up some of the things.
One thing bugs me though, FTA:
How is this accomplished? I know that CMB anisotropies are quantitatively obtained by perturbing the metric, but afaik no abundances nor densities don't kick in the derivation.
In particular, how does baryon (or, as I am already at it, any species of particles) number density affect CMB energy spectrum?
Disclaimer: I have only read first 100 p of Dodelson and only glimpsed at later chapters. If there is no short answer, then don't bother answering to these questions.
Don't you mean Bose-Einstein distribution?Mordred said:In thermal equilibrium this is described as a Bose-Einstein condensate with a fermi-Dirac distribution.
Thermalization of photons is the process by which photons, which are particles of light, reach a state of thermal equilibrium with their surroundings. This means that the photons distribute their energy in a way that is consistent with the temperature of their environment.
Factors that affect the thermalization of photons include the temperature and density of the environment, the energy level of the photons, and the type of material they are interacting with. These factors determine how quickly the photons will reach thermal equilibrium and the distribution of their energy.
Thermalization of photons occurs through a process known as scattering, where the photons interact with particles in their environment. These interactions cause the photons to lose or gain energy, and eventually reach a state of equilibrium with the surrounding particles.
Thermalization of photons is a crucial process in understanding the behavior of light in various environments. It explains how light is absorbed, emitted, and scattered by different materials, and plays a vital role in many scientific fields, including astrophysics, atmospheric science, and materials science.
Yes, thermalization of photons can be reversed through a process known as de-thermalization. This involves manipulating the environment or properties of the photons to redistribute their energy and break the state of thermal equilibrium. This process is essential in technologies such as lasers, which require the photons to be in a non-thermalized state.