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Suekdccia
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- Photons being blueshifted when crossing voids due to Rees-Sciama effect...?
I was reading this paper (https://academic.oup.com/mnras/article/288/2/387/960778) where they analysed how CMB radiation is affected by evolving voids in an expanding spacetime (particularly through the Rees-Sciama effect and the integrated Sachs-Wolfe effect).
This effect predicts that photons crossing well potentials would be blueshifted and the ones crossing voids would be redshifted. However, in this paper (and some others: https://arxiv.org/abs/astro-ph/0612347, https://pure.port.ac.uk/ws/portalfiles/portal/6034571/Alvise_Raccanelli_Thesis.pdf) the authors indicate that there can be a partial cancellation of the redshift of photons crossing the voids (or said in another way, that growing voids can blueshift photons).
My question is:
Can there be cases where the photons crossing the voids have a total net blueshift as they get out of them?
This effect predicts that photons crossing well potentials would be blueshifted and the ones crossing voids would be redshifted. However, in this paper (and some others: https://arxiv.org/abs/astro-ph/0612347, https://pure.port.ac.uk/ws/portalfiles/portal/6034571/Alvise_Raccanelli_Thesis.pdf) the authors indicate that there can be a partial cancellation of the redshift of photons crossing the voids (or said in another way, that growing voids can blueshift photons).
My question is:
Can there be cases where the photons crossing the voids have a total net blueshift as they get out of them?