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I have read online that light can produce a weak gravitational field (for example antiparallel beams should, in principle, attract weakly).

This made me wonder if light can produce minute gravitational waves?

Even if the waves were extremely weak (no disregarding of those high order terms in the applicable equation, whatever equation that may be), could the gravitational waves dissipate energy (on the order that is expected for cosmological redshifts) when light travels across cosmological distances?

I was thinking about the debunked tired-light hypothesis regarding the cosmological redshift, and I wondered if anyone has considered a mechanism whereby gravitational waves dissipate energy.

Qmechanic
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Dan
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1 Answers1

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The class of spacetimes that model the gravitational effects of massless radation are called "pp-wave spacetimes". They have a lot of interesting properties that make them worth studying. However, they do not dissipate energy, they transport it in the same way that other waves transport energy.

However, if you would like to model the cosmic microwave background radiation then a null dust spacetime will probably be more reasonable than a pp-wave spacetime. These two classes of spacetimes are closely related since any pp-wave spacetime can be interpreted as a null dust spacetime.

DaleSpam
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