About Me

I am a researcher in cosmology currently based in Portsmouth in the UK, where I hold a Marie Skłodowska-Curie fellowship and the Dennis Sciama fellowship at the Institute of Cosmology and Gravitation (ICG).

I have previously held positions at the University of Helsinki and the Helsinki Institute of Physics, and at the University of Bielefeld. I received my PhD (or DPhil, as it is known there) at the University of Oxford, where I was at Merton College. My DPhil supervisor was Subir Sarkar. Before that DPhil I took an undergraduate degree in physics from St Stephen's College, Delhi University, and an MPhys from Oxford (at Trinity College).

I am interested in several different aspects of cosmology, including cosmic voids, large-scale structure and its effects on the cosmic microwave background radiation (CMB), gravitational lensinginflation, models of modified gravity, and observational tests of all of the above. Being based at the ICG, I am also a now a member of SDSS-IV and DES, and have begun to contribute to some analyses for these collaborations.

Outside physics, I am interested in mountains, mountaineering, climbing and exploration of all kinds, and books about all of the above. In the summer I play a lot of cricket (something I was even able to do in Finland!).


  1. I would like to share something that I hope someone can provide an answer.
    The double slit experiment. I can't seem to wrap my head around it. I just don't buy it. I understand what they are arriving at, but each time I think about it I can come up with lots of scenarios that would just not make sense. Look at this scenario and think if you agree with me...

    You have detectors on each slit of a double slit experiment
    The detectors are connected to a computer.
    You can see the actual interference pattern or no interference pattern from the laser being sent through the two slits.

    What they are saying is... If the computer is on examining the result, you will not see an interference pattern. If the computer is off not examining which way the particle went through, you will see an interference pattern.

    I believe this is the fundamental thing they are trying to say. If you examine it, you will not see an interference pattern (it becomes a particle). If you don't examine which slit it went through you WILL see an interference pattern (like a wave).

    Is that logical? It sounds B.S. Lets say I am looking at the interference pattern. (computer is not collecting info). They are saying if I press a key at the keyboard that allows you to start collecting data, at that moment, the interference pattern will magically turn into a non-interference pattern. The detector is passive. All it does is detect or not detect. Turning on the computer with a keypress will in the end change physical properties of the photo or electron? That is just pure BS.

    Please someone explain what is wrong. I am looking at the interference pattern with my eyes. Because of a keypress of a keyboard, my eyes will magically see the interference pattern change into a non-interference pattern? When there is no physical movement of the detectors (it is passive). The only change is that the computer is now collecting data because of a keypress. Either the experimenters don't know how to do experiments, or maybe they are explaining it wrong. Because it is just NOT possible how they are explaining it.

    1. Hello pohanlin. I'm not going to provide a very detailed answer to your long question, because this is not really a forum for discussion about the basics of quantum mechanics. There are many, many, books and online resources where you can learn more.

      However, two things you might wish to consider as you read more about the double slit experiment. Firstly, Nature has no obligation to make logical sense to you. What happens in a experiment is what happens in the experiment; if this contradicts your prior intuition of what should be considered "logical", then you should consider reassessing that intuition.

      Secondly – and this is probably more to the point - you might want to ask yourself what kind of an instrument might be able to "detect" the passage of an electron. Is "passive" detection possible, or must detection involve some interaction with the electron? Is it possible to interact with something without affecting its physical state?

      I hope that helps, and have fun finding out more!

  2. Good answer.

    I do believe this experiment does demonstrate basic and logical principals of mechanics. What I believe it shows is that A. it is not possible to detect without interaction and that every action has a cause and effect though equal not neccessarily scalable on a specific event. B. events are relative only to the present state and that each present state is infinitely different.

    The question I might consider is if the experiment cannot define a path from an origin at a particular time, from location on the screen; are we looking in the wrong place. Would it make sense that its origin is from within and is it only relevant to the observer present state.

  3. "Outside physics, I am interested in mountains, mountaineering, climbing and exploration of all kinds, and books about all of the above. I spend much of my spare time reading."

    Have you read the book The Fourth Part of the World? I've always been interested in maps, but this book is more interesting than most. Another recommendation: The Map That Changed the World.