The Integrated Sachs-Wolfe Effect:

Origin, Status and Future

Developed by David Miller in fulfillment of the requirements of ASTR 282 with Wayne Hu


    The integrated Sachs-Wolfe (ISW) effect is a gravitational effect experienced by the cosmic microwave background (CMB) photons as they travel to the observers today from the surface of last scattering (SLS) at recombination.  Under the most naive assumptions about the universe, this effect is nonexistent.  However, recent observations of the acceleration of the universe have led to the belief that there is a non-trivial smooth energy component in the universe, the so-called Dark Energy. Such a component is thought to be responsible for the recent acceleration, and would also, therefore, lead to a mechanism for the ISW effect.  The mysterious nature of dark energy has thus led to unending speculation about its origin, dynamics and implications for the fate of the universe.  The possibility of learning about the dark energy through its indirect effect on the CMB photons is a tantalizing possibility, indeed. 


    It is to this end that this website is dedicated, with the hope that an understanding of the ISW effect's origin, the possibilities of its detection and the information it conveys about the nature of the dark energy may assist us in better understanding the universe in which we all live.


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