Dark Matter Map Confirms Einstein's Theories Through Cosmic Microwave Background

A recent dark matter map supports Einstein's theories by showcasing its gravitational lensing effect on cosmic microwave background (CMB) radiation. Utilizing data from the National Science Foundation's Atacama Cosmology Telescope (ACT), over 160 researchers constructed the CMB map, representing light emitted just 380,000 years after the Big Bang.

This ancient light journeyed through the universe for nearly 14 billion years before being detected by Earth-based telescopes. During its voyage, the CMB passed through galaxy clusters and dark matter, experiencing the influence of these massive structures.

In accordance with Einstein's General Relativity principles, light is distorted and magnified due to the gravitational force exerted by massive objects, a phenomenon known as gravitational lensing. The CMB is similarly affected by the universe's matter, including dark matter, which also generates gravitational lensing.

By studying gravitational lensing in the CMB images, researchers detected distortions in the early universe's light caused by vast amounts of unseen matter. The findings reaffirmed Einstein's theories, aligning with General Relativity's predictions.

Mathew Madhavacheril, a Princeton postdoctoral fellow and lead author of one of the research papers, stated that the new map aligns with the standard model of cosmology based on Einstein's gravity theory regarding the universe's irregularity and growth rate.

The universe's irregularity refers to the discrepancy between the CMB image and the current universe's matter distribution. Fossil light exhibits a relatively smooth temperature distribution, contrasting with the existing structures of galaxies, stars, and planets, a conundrum known as "the great cosmological crisis."

Previous observations suggested that dark matter's irregularity was insufficient, exacerbating the discrepancy. However, the new map offers fresh insights, revealing that the observed dark matter aligns with theoretical predictions.

Source: Princeton University

Researchers used the Atacama Cosmology Telescope to create this new map of the dark matter. The orange regions show where there is more mass; purple where there is less or none. The typical features are hundreds of millions of light years across. The whitish band shows where contaminating light from dust in our Milky Way galaxy, measured by the Planck satellite, obscures a deeper view. The new map uses light from the cosmic microwave background (CMB) essentially as a backlight to silhouette all the matter between us and the Big Bang. “It’s a bit like silhouetting, but instead of just having black in the silhouette, you have texture and lumps of dark matter, as if the light were streaming through a fabric curtain that had lots of knots and bumps in it,” said Suzanne Staggs, director of ACT and Princeton’s Henry DeWolf Smyth Professor of Physics. “The famous blue and yellow CMB image is a snapshot of what the universe was like in a single epoch, about 13 billion years ago, and now this is giving us the information about all the epochs since.” Credit: ACT Collaboration