SuperStructure Imprint & ISW

" An Imprint of Super-Structures on the Microwave Background due to the Integrated Sachs-Wolfe Effect"

is the name of article published by IFA Hawaii university physics department collegues Benjamin R. Granett, Mark C. Neyrinck, István Szapudi (IFA, Hawaii).

the lanel address is : arXiv:0805.3695

This physicist use Integrated Saches Wolfe effect first introduced by RainerKurt Saches and Arthur Michael Wolfe in 1968 to show the imprint of superclusters and supervoid on photons energy , coming from Last scattering surface.

This imprint which is detected by founding the correlation of CMB temprature fluctuations and galaxy number densities/from SDSS galaxy catalouge/ is a key observation for accelerating universe.

This imprint is in good agreement with the dark Energy assumption and accelerating universe.

Ok what is the story.

The story is easy to grasp.

If the photons travel to the gravitational potentials, they gain energy and have a blue shift in wavelenght in contrast ,if photons come up from potentiel well,they loss energy and has a reshift.Now the point is that ,if the universe is filled with dark matter in linear regime,there is no difference between the change of energy of photons when they are going in and coming outside a gravitational well/cluster/.BUT...

the interesting part of the story is when the universe is accelerating,so in meanwhile that photons live in the potential well,Dark energy -cosmological constant or ...causes the well to be shallowed and become less deep.So there is a difference between energy gain and loss for photons so we can see this imprint on CMB photons and that is the evidence of Accelerating universe.

Good and joyful part of the story is this that the ISW can be used as one of the probes of Dark energy because oit is measuring some quantity/fluctuation of tempreture and it's coreelation/in two different stage of universe.So it can tell us about the dynamic of this exotic dark component of the universe.

IFA team launch a website about the superclusters/over dense regions/, super voids as a tool to exploring the dark matter and dark energy in the universe also explaining the ISW effect and their work on last paper.The site is : http://ifa.hawaii.edu/cosmowave/supervoids/