Research

Our research interests lie in understanding the fundamental interactions in nature: electromagnetic, weak, strong and gravitational forces.

Quantum Field Theory

Quantum field theory provides a unified description the first three fundamental interactions — the Standard Model of Elementary Particles.

Quarks and leptons form the fundamental building blocks of matter. Arranged in three generations, the first generation contains the most stable particles that constitute all stable matter in the Universe. Quarks exist in three different “colors” and combine to form colourless entities. Leptons, including the electron, muon, tau, and their respective neutrinos, exhibit different electric charges and masses.

Four fundamental forces govern the Universe: gravity, electromagnetic, weak and strong forces, each varying in strength and range. Three of these forces, excluding gravity, result from the exchange of bosons, particles that transfer energy in discrete amounts. The strong, electromagnetic, and weak forces are carried by the gluon ($g$), photon ($\gamma$), and $W$ and $Z$ bosons respectively.

The Higgs boson ($H$), a key element in the Standard Model, is pivotal to understanding the origin of particle mass. This particle, theorized by Peter Higgs and others, was finally discovered at CERN’s Large Hadron Collider in 2012. Its detection verified the existence of the Higgs field, an energy field pervading the universe. When other elementary particles interact with this field, they acquire mass, with more interaction leading to greater mass. Although the Higgs boson’s discovery fills a crucial gap in the Standard Model, the theory still doesn’t incorporate gravity and leaves numerous fundamental questions unanswered.

Einstein’s General Relativity

General Relativity, a profound theory put forth by Albert Einstein in 1915, reshapes our understanding of the universe’s most fundamental aspects. Physicist John Archibald Wheeler beautifully summed it up: “Spacetime tells matter how to move; matter tells spacetime how to curve.”

Let’s break this down. Picture a stretched sheet representing spacetime, the combined entity of the three dimensions of space and one of time. Place a heavy object, like a bowling ball (representing a massive celestial body), on it. It will sink down, distorting the sheet. This is matter telling spacetime how to curve.

Now, if you roll a smaller ball (a less massive object) onto the sheet, it will naturally travel along the curve towards the larger object, as though drawn by an invisible force. This is spacetime telling matter how to move. In essence, what we perceive as gravity is just this interaction between matter and curved spacetime.

Einstein’s General Relativity is an elegant interplay of matter and spacetime that helps us comprehend the deepest mysteries of the universe, from the motion of galaxies to the behavior of black holes.