Research 

Dark Energy

More than two decades ago, astronomers discovered that the Universe’s expansion is speeding up. This finding reshaped cosmology and raised one of the biggest questions in physics: 

✨ What is causing this acceleration? 

The simplest idea is the cosmological constant, a uniform energy built into space itself. But observations leave room for richer possibilities:

• The acceleration could come from a new, evolving form of energy.

• It could signal a breakdown of Einstein’s theory of gravity at the largest scales. 

• Or it could be the result of hidden interactions between the Universe’s invisible components.

While the cosmological constant is elegant, it offers no explanation for its tiny value or why it becomes important only now in cosmic history.

I study broader dark energy models 🔭  that allow their properties to change with time. These include, but are not limited to, scalar fields, as well as fluid-like descriptions that capture a wide range of possible behaviors. 

Modified Gravity Theories 

Einstein’s General Relativity has passed every test inside the Solar System, but cosmic acceleration could be a clue that gravity behaves differently over billions of light-years.

I investigate modified gravity theories from geometrical extensions of spacetime to models that directly couple gravity with the matter content of the Universe. The goal is to see if changing the rules of gravity can explain cosmic acceleration without introducing exotic new energy. 

In the standard picture, dark matter and dark energy act independently: one clumps into structures, the other drives expansion. But physics doesn’t forbid them from exchanging energy or momentum.

I explore interaction models where the dark sector behaves more like a connected system than two isolated components. Such interactions could help resolve observational tensions and give us new clues about both dark matter and dark energy. 

I compare these models with high-precision measurements from:

• Baryon Acoustic Oscillations (BAO): cosmic “yardsticks” imprinted in the galaxy distribution. 

• Supernovae Type Ia: standard candles that map out the expansion history. 

• Cosmic chronometers: galaxies used to measure the Universe’s age at different epochs.

• Cosmic Microwave Background (CMB), the afterglow of the Big Bang, giving a precise picture of the early Universe. 

Statistical tools like Bayesian model comparison allow me to see which ideas fit the data best, and which fail.