The MINER detector is used to search for low-energy neutrinos at the TRIGA reactor at Texas A&M University. This sapphire detector is not only capable of detecting reactor neutrinos, but also plays a role in the search for dark matter, which could lead to breakthroughs in new physics and aid in nuclear nonproliferation monitoring.

Mysteries of the Universe: Dark Matter and Dark Energy

Despite significant progress in space exploration, modern science covers only a small fraction of the full picture. About 95% of the Universe consists of dark matter and dark energy, while the ordinary matter we are familiar with makes up just 5%. Dr. Rupak Mahapatra, an experimental particle physicist at Texas A&M University, is working to uncover this hidden part by developing advanced semiconductor detectors with cryogenic quantum sensors. These technologies support experiments worldwide and help scientists delve deeper into one of the greatest mysteries in science.

Mahapatra compares humanity’s limited understanding of the Universe to a well-known parable: “It’s like trying to describe an elephant by only touching its tail. We sense something vast and complex, but perceive only a small part of it.” Recently, his work and that of his colleagues was published in the prestigious journal Applied Physics Letters.

What Are Dark Matter and Dark Energy?

Dark matter and dark energy are so named because so little is known about them. Dark matter makes up the bulk of the mass in galaxies and their clusters, playing a key role in shaping their structure across vast cosmic distances. Dark energy is the force responsible for the accelerating expansion of the Universe. Simply put, dark matter acts as a cosmic glue, while dark energy causes space to expand ever faster.

Although both components are extremely widespread, neither dark matter nor dark energy emits, absorbs, or reflects light, making them extremely difficult to observe directly. Scientists study their effects through gravity, which determines the motion of galaxies and the formation of large-scale structures. Dark energy accounts for about 68% of all the energy in the Universe, while dark matter makes up roughly 27%.

Detectors for the Invisible

The work of Mahapatra’s group at Texas A&M University can be compared to trying to “catch a whisper in a hurricane”—their detectors are exceptionally sensitive. These devices are designed to register particles that interact with ordinary matter extremely rarely, and such interactions could provide the key to understanding the nature of dark matter.

“The problem is that dark matter interacts so weakly that we need detectors capable of recording events that might happen once a year or even once a decade,” Mahapatra notes. His team has participated in the world’s leading search for dark matter using the TESSERACT detector. “It’s all about innovation. We’re looking for ways to amplify signals that previously got lost in the noise.” Texas A&M University is part of a select group of institutions involved in TESSERACT experiments.

Pushing the Frontiers of Science

Mahapatra’s current efforts build on decades of experience in refining particle detection methods. Over 25 years, he has participated in the SuperCDMS experiment, which conducted some of the world’s most sensitive dark matter searches. In a landmark 2014 article published in Physical Review Letters, Mahapatra and his colleagues presented a method for calorimetric ionization detection using voltage in the SuperCDMS experiment. This breakthrough made it possible to study low-mass WIMPs—one of the main candidates for dark matter—significantly expanding scientists’ ability to detect previously inaccessible particles.

In 2022, Mahapatra co-authored another study that examined various approaches to searching for WIMPs, including direct and indirect detection as well as collider experiments. The work highlights the importance of combining different strategies to solve the dark matter puzzle.

“No single experiment will give us all the answers,” says Mahapatra. “We need synergy between different methods to piece together the full picture.”

Why It Matters

Understanding dark matter goes far beyond academic curiosity—it could reveal the fundamental principles that govern the Universe itself. “If we can detect dark matter, we’ll open a new chapter in physics,” Mahapatra believes. “Searching for it requires extremely sensitive technologies, and this could lead to discoveries we can’t even imagine today.”

What Are WIMPs?

WIMPs (Weakly Interacting Massive Particles) are considered one of the most promising hypotheses to explain dark matter. These hypothetical particles interact through gravity and the weak nuclear force, which explains why they are so difficult to detect.

Why It Matters

If WIMPs exist, they could account for the missing mass of the Universe.

How the Search Is Conducted

Experiments like SuperCDMS and TESSERACT use ultra-sensitive detectors cooled to near absolute zero to capture the rare interactions between WIMPs and ordinary matter.

The Main Challenge

WIMPs can pass through the Earth without leaving any trace, so researchers may need years of data to record even a single event.