For decades, physicists have been endeavoring to accommodate quantum mechanics, the physics of the minimal, with gravity, the physics of the very large. While numerous academics are working on quantum gravity, they frequently use models that don’t think about specific parts of our own universe, similar to its accelerated expansion.
Now, a team of scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) reports a new approach to quantum gravity using a model that more closely matches our reality.
Scientists scattered matrix for massless fields, or S-matrix, an articulation that predicts what will happen when particles at infinitely far distances meet up, cooperate, and continue on ahead. Meanwhile, the S-matrix uses starting points to foresee results. Significantly, this idea can apply to a de Sitter space, a universe that is growing at an accelerating rate—simply like our own.
In this study, scientists calculated the S-matrix in de Sitter space for the simplest scenario, involving free, non-interacting particles. This expression is known as free S-matrix.
Adrian David, one of the authors of the study, said, “The free S-matrix is more than just elegant math—it has the potential to explain more realistic scenarios. We will now start thinking about such scenarios, moving beyond individual fields to explore what happens when those fields interact.”
“The free S-matrix is like a “Hello, World!” program used to the math in a simple context.”
“Like a sanity test in computer programming, the output ‘Hello, World!’ message is less interesting than the underlying language used to create it. Likewise, the free S-matrix is less appealing by itself, but more in the questions, it might allow us to answer.”
Yasha Neiman, head of the Quantum Gravity Group said, “We are in a universe that is expanding at an accelerating rate, a de Sitter space, and it appears that these conditions are now permanent. This information must be incorporated as a cornerstone in our description of reality.”
Currently, scientists are working on the next step of the problem—applying the free S-matrix to more complicated scenarios that echo reality. Then, they might gain a better understanding—is this merely gorgeous math or more than just a pretty face?