My name is Daniel Töyrä and I am a PhD student within the Gravitational Wave Initial Training Network (GraWIToN), funded by the European Commission under the Marie Skłodowska-Curie actions. I'm hosted by the University of Birmingham in the United Kingdom where I work with computational modelling of advanced laser-interferometric gravitational wave detectors.

As a member of the LIGO Scientific Collaboration (LSC), one of the goals of my project is to contribute with computational models and simulations to the two Advanced LIGO detectors built mainly by Caltech and MIT. Each of these state of the art devices consists of two perpendicular arms of equal lengths forming an L. If a gravitational wave passes by the detector, it will stretch one arm as it contracts the other. The magnitude of the length change is proportional to the total length. Advanced LIGO uses 4 km long arms, which would make a fairly strong gravitational wave induce a length change in the order of 10-18 m, which is less than one-thousandth of the radius of a proton. However, the devices are capable of measuring length shifts all the way down to 10-18 m.

The length measurements are performed by using laser interferometry. That is how it works: a laser beam is split up into two equal parts by a beam splitter before the beams are sent into different arms. Each arm is a long vacuum chamber with two mirrors inside, one in each end. This constitutes an optical cavity (Fabry-Perot cavity) where the beam is trapped (it bounces back and forth) for some time before it leaks out and returns to the beamsplitter, where it is recombined with the beam returning from the other arm. The system is designed in such a way that the two beams cancel each other (destructive interference) if the arm lengths are equal. But if something, hopefully a gravitational wave, slightly changes the arm lengths, the beams do not cancel each other anymore and an output beam can be detected.

In Birmingham I'm part of a group working with gravitational wave optics. We all have our own main projects that we are responsible for, but we are also working as a team by involving the whole group in all projects. I find the working environment in the group and at the university very inspiring: there are many experienced and enthusiastic scientists, which I feel privileged to work with.

My time as an early stage researcher in GraWIToN started with one-week introductory course on the field of Gravitational waves, held at the University of Birmingham. This was a nice way to get a broader understanding of the topic before diving into my own sub-field. The course was also good for getting to know my new colleagues. Since then I have mainly been learning the basics of the Frequency domain INterfErometer Simulation SoftwarE (FINESSE) that I will use, maintain and develop during my time in Birmingham. Together with a fellow, a first year PhD student, I have performed simulations of a table top experiment involving an optical cavity that one of our colleagues is working on. This has been a good way to make us feel somewhat useful and involved in the group activities while still working on becoming useful for real.

I think this is a very interesting time to work in the field of gravitational waves. The field is expanding rapidly, Advanced LIGO and Advanced VIRGO are soon to be operational, and the forecast for a direct gravitational wave detection during my time as a PhD-student is looking promising. Furthermore, I am grateful for the opportunity to experience how it is to live and work outside my native country of Sweden.

Thank you,
Daniel Töyrä

New Year, new life! I arrived in Hannover just after New Year’s and soon began my work at the Albert Einstein Institute (AEI). It’s been less than one month, but I have already had the chance to discover some new physics and culture. The move from Brazil to Germany has been very smooth and I received a lot of support from the International Office of the Institute and from my colleagues, helping me with all details, from getting a visa to finding a nice flat.

My first month of research has been dedicated to theoretical studies of laser interferometers for detection of gravitational waves. I specifically focused on techniques of laser power stabilization, which are also the theme of my PhD research. Such techniques are extremely important in improving the sensitivity of gravitational wave detectors, which makes it a very interesting field to work with.

During this first month I also had the opportunity to attend some great lectures presented by gravitational wave researchers, both from the AEI and abroad. The AEI has a very friendly atmosphere and discussions about Physics happen all the time, which makes it easier to understand new concepts. One example is the weekly group meeting, where we discuss our current work and related problems with other members of the group and learn more about their projects as well.

In the next weeks I will start working in the lab, as I will join another PhD student on laser stabilization experiments. This will also provide me with practical skills for my PhD project. It is an honor to be funded by Marie Curie Actions and to work in such a stimulating environment. I am very excited for the next few years, because of the opportunity to do great science as well as the potential for personal development.

Every night the beauty of nature occupies the sky with a fascinating view of our universe. How many mysteries are still to be revealed?

Gravitational waves are among the most interesting phenomena predicted by General relativity, Einstein's theory of gravity, and I am really glad to be involved in such an attractive field. My name is Serena Vinciguerra and I am one of the early stage researchers supported by the European Marie Curie project "GraWIToN". At the beginning of November I started my collaborative work on the detection of gravitational waves by ground based detectors at Birmingham University. This is a particularly exciting period for gravitational wave research, indeed a new generation of interferometers (advanced LIGO and Virgo, KAGRA) will soon be ready to collect new data with an increased potential for discovery. These instrumental updates open up new possibilities which have to be supported by innovative and effective data analysis projects. I’m involved in one of the most fascinating branches of these analyses, in my opinion. During these few months my work has had the purpose of speeding up the algorithm aimed at the detection of gravitational waves emitted by compact binary coalescences. These astrophysical systems are composed by two extremely massive objects, like neutron stars and black holes; they are among the most promising sources for ground based interferometers.

At the School of Physics and Astronomy of Birmingham University I have found a very active environment, where people coming from different parts of the world have the pleasure of collaborating to improve our knowledge
of the Universe. Meetings and talks are the order of the day making this place very fruitful and full of new ideas. It is an ideal environment to follow astronomy and physical passions while developing culturally.

The scientific community is composed of people with different experiences and backgrounds but all of them are very available and happy to help. I am also very impressed by the fresh environment and by the attention that is given here to the young generation. An incredible amount of opportunities to improve our abilities and knowledge are proposed: discussion activities, presentations, collaborative events, teaching and so on. The School of Physics and Astronomy offers a very broad range of fascinating subjects, which are often presented with talks to create a common background for everyone.

The many different cultures, beautifully mixed together, are an important inspiration for the creation of such a rich academic life. This is one of the main reasons why people should move and travel, to share their own cultures and learn about others.

I think that my generation and the following should feel part of “our homeland Europe” (“la nostra patria Europa” -cit De Gasperi, 1954). Europe is more than politics, it should become our community. The Marie Curie project, which is supporting my PhD at Birmingham University, illustrates this idea well. It means not only economic support but also the opportunity to participate in various activities, from talks and presentations to charity events, such as the recent cake sale for Birmingham Children's Hospital.

In light of this European idea, I hope that this and similar projects will be broadcasted and valued even more in the near future. I hope that this international experience will open up new opportunities for me for the future, maybe to continue working in this research field and hopefully again in Italy.

Whatever the future will hold I am sure that this period of my life will be very important for me, as it will for for all the people who have the courage and the opportunity to engage in similar adventures.

First trip to EGO/Virgo

On 9th December, I began an exciting trip from L’Aquila to Pisa, which was also my first trip in Italy. We would be in Cascina for 2 days for Virgo meeting.

As a PhD student of GraWIToN project, now I study in Gran Sasso Science Institute (GSSI). It was an exciting experience to visit the EGO/Virgo. I knew the Virgo several years ago, when I just began my master program to study the gravitational waves, which is in progress of a very challenging experiment.

When we arrived at EGO/Virgo in the morning of 10th, I was still impressed by the 3 kilometers interferometer arms, even I have heard of the Virgo configuration many times. In these apparatuses, the experimental physicists are preparing the most precise measurements in the world, which can be used to listen to the musical notes of the universe. Now it’s being upgraded to the advanced gravitational waves detector phase.

In the coming several years, a new observatory window will open up onto the universe. I can imagine that it will give us information of the most dramatic events in our universe and deeply improve our understanding of the cosmos. I feel lucky and honoured to participate in this promising research.

Thanks to Dr. Michele Punturo to drive us to EGO, and introduce the Virgo and members to us!

When the sun sets behind the horizon ranges in the distance and the darkness slowly spreads across the silent field, the splendour sunset glow goes over the EGO and Virgo.