Dark Matter

The field of cosmology has come a long way toward understanding the universe as a physical system: we’ve mapped its history and structure in great detail, we know what it went through since a few seconds after its birth until today, we understand...

Five years ago, NASA’s Fermi Gamma-ray Space ­Telescope saw more gamma rays than expected from the area around the center of our galaxy. Many scientists suggest that the extra gamma rays could be from the annihilation of dark matter particles. This...

In 1913, Victor Hess measured the background level of atmospheric ionization while ascending with a balloon. By doing so, he discovered that Earth is continuously bathed in ionizing radiation. These cosmic rays primarily consist of protons and...

The theoretical astrophysicist and Princeton University professor is well known for his work on NASA’s 2001 Microwave Anisotropy Probe—he conceptualized the mission and deciphered the radio telescope’s data to measure the age of the universe, the...

In the public lecture “The Latest News from the Cosmos,” Matias Zaldarriaga, Professor in the School of Natural Sciences, explores the most detailed map of the infant universe to date. Publicly released on March 21, 2013, the map shows relic...

Following the discovery in July of a Higgs-like boson—an effort that took more than fifty years of experimental work and more than 10,000 scientists and engineers working on the Large Hadron Collider—Juan Maldacena and Nima Arkani-Hamed, two...

Why is the expansion of the universe speeding up, instead of being slowed by the gravitational attraction of galaxies and dark matter? What is the history of the Milky Way galaxy and of the chemical elements in its stars? Why are the planetary...

For slightly over a year, I have largely put aside my longtime interests in the foundations of quantum mechanics and in particle physics, and have been working on dark matter. This interest came about in two different ways. The first was a paper on...

One of the remarkable discoveries in astrophysics has been the recognition that the material we see and are familiar with, which makes up the earth, the sun, the stars, and everyday objects, such as a table, is only a small fraction of all of the...

In the public lecture “The World’s Largest Experiment,” Nathan Seiberg, Professor in the School of Natural Sciences, discusses the Large Hadron Collider (LHC) and the potential discoveries it may yield—among them, new insights about the origin of...