Quantum Diaries

Salvish Goomanee, an undergraduate theoretical physics student, penned the following post about his summer research at King’s College London.

Salvish Goomanee

This past summer, I had a brief glimpse into what it’s like to carry out theoretical research. As an undergraduate, this was an exciting foray into what I hope will be my future! The work was done under the supervision of a research associate of the theoretical physics department at King’s College London, who was kind enough to accept my proposal. We decided to look at some perturbative amplitudes of the open bosonic string, which gave me the chance to peek into the obscure world of quantum strings. (Bear with me – I’ll explain what all that means soon enough!) I was presented with several very interesting challenges during the course of the research; it was not always easy but it was great to have the chance to experience with the various mathematical methods that permeate the fundamental formalism of string theory.

After our first meeting, which lasted for about three hours, I found myself with notes and calculations and a long list of references which seemed to be the basics for understanding perturbative string theory. I obviously was not aware of what was going on but this was the beginning of the three long months of studying the new and rigorous concepts of quantum field theory and some slightly more advance mathematics as well. The goal of the research was to understand the path integral formulation and apply it to the framework of the bosonic string.

In short, bosonic string theory is a type of string theory that deals only with bosons which are integer spin particles. To understand that a bit better, let’s leave string theory for a brief moment and consider the construction plan for a new building. Architects and engineers will work out a much smaller model first (which I am sure we have all seen!), where it would be much easier to have control upon and therefore have a better understanding how things will look like at much larger scales. Physicists will do the same thing as calculations for the bosonic string can be performed at energy scales that are relatively low. Therefore amplitudes calculated via small perturbations can be pictured as new particles. Quantum field theory is extensively employed during such processes. (Quantum field theory is basically the merging of special relativity and the laws of quantum mechanics. String theory is actually a quantum field theory that incorporates gravity which the Standard Model of particle physics does not!)

So, here I was, an undergraduate who just finished the second year exams, facing all this new stuff that I had to study and make sense of. It was challenging and somehow a bit frightening. You reach a point where you ask yourself why you should continue doing these things when it was not making much sense, but giving up was not an option! The good thing was that I would be able to finally apply the few little things I learnt from relativity (field equations, cosmological solutions and tensors, etc). Being familiar with the theory of geometrization of space-time proved to be a very good support as the notation used in perturbative string theory was then much easier to understand. It’s actually extensively employed everywhere in theoretical physics. Finally we were then able to see (and I was able to contemplate!) the various predictions, good and bad, of string theory.

This experience was something which I definitely enjoyed. I guess what made it better was the great summer we had here in London. Obviously during the hottest days we could not (and did not want to) really work inside, so we discussed our ideas our outside. One day we even spent more than four hours talking; this was one of the rare moments where an undergraduate gets to know in a bit more detail the kind of research their supervisors and lectures carry out and the level at which it is done. In the end, I was able to produce a report in which I discussed the stuff we went through. We are now looking at some other applications of the quantum strings in greater detail. All in all, it was a wonderful summer, and I’m thrilled that we’re still collaborating!

Living in an era when the latest discoveries in physics regularly make headlines, it can be easy to miss the individual contributions from the scientists and institutions around the globe making these advances possible. Highlighting these contributions, along with the quirky world from physicists working behind the scenes, has been the focus of Quantum Diaries since it launched in 2005.

Quantum Diaries is sure to continue in that role, but today relaunches with four physics laboratories in its ranks: Brookhaven, CERN, Fermilab and TRIUMF. Each of the laboratories will be posting regular updates to Quantum Diaries.

All of the labs have already gotten started. In its first post, Brookhaven Laboratory provides a thorough description of its current physics work. CERN, aware of the challenges of fitting complex scientific explanations into 140-character tweets, hopes this new forum will give the laboratory a place to expand on the news of the day coming from the LHC and other experiments. Fermilab details a number of expectations for 2011, including updates on the Higgs search, more data from its neutrino experiments, the launch and construction of several experiments, and a decision that the Tevatron will shut down in September 2011. Finally, Canadian physics laboratory TRIUMF explores the difficulty of summing the full range of its work, from manufacturing isotopes to treating eye cancer, in a single catchy name.

As these laboratories continue to contribute to the site, Quantum Diaries welcomes commenting, feedback and constructive discussions on each post. Check back for frequent updates from our new laboratory members, as well as continued updates from our regular Quantum Diaries bloggers.

Brookhaven

Brookhaven National Laboratory is a multipurpose research institution funded by the U.S. Department of Energy. Located on Long Island, NY, Brookhaven operates large-scale facilities for studies in physics, chemistry, biology, medicine, applied science, and advanced technology. The Laboratory's almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.

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CERN

CERN is one of the world's largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world's largest and most complex scientific instruments are used to study the basic constituents of matter: fundamental particles.

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Fermilab

What is the nature of the universe? What are matter and energy, space and time? At the U.S. Department of Energy's Fermi National Accelerator Laboratory, thousands of scientists from universities and laboratories across the United States and around the world collaborate on experiments to discover what the universe is made of and how it works.

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TRIUMF

Located in Vancouver, British Columbia, TRIUMF is Canada's national laboratory for particle and nuclear physics. The laboratory is owned and operated as a joint venture by a consortium of 16 Canadian universities and celebrated its fortieth anniversary in 2009. TRIUMF brings together dedicated physicists and interdisciplinary talent, sophisticated technical resources, and commercial partners in a way that has established the laboratory as a global success.

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