Here is an announcement of a program I will be organizing at the KITP from Jan 17 thru March 9 2012. It is a program on numerical methods for gravity and QFT. The web page of the program is located here.
Here is the image I made to illustrate the program: it is generated by taking a set of modes in a box with a UV cutoff. Then amplitudes are seeded for these modes with random numbers and phases multiplied by the typical quantum uncertainty on each mode. The result is a picture like the one below.
It is also fun to animate it.
Right now I have to start chasing people and reminding them that the (first) deadline for applications is coming soon (April 30th).
In the meantime stay tuned.
Image of Fluctuations of quantum fields
Bizoń and Rostworowski have just published a numerical study which suggests that AdS is unstable against small perturbations in classical GR: arxiv.org/abs/1104.3702
What do you think about it?
Hi Wolfgang:
Without having read the paper in detail:
Global AdS has a positive energy theorem that shows that AdS is the vacuum (lowest energy state).
Linearized perturbations seem fine.
Small perturbations might still do something funny if non-linearities are important. From their paper it seems that this is what happens. The non-linearities take energy from low modes and dump them into high modes (you can think of this as a classical analog of the UV catastrophe, preventing the system from thermalizing). This gets fixed by leading quantum effects. I would not worry.
I have never understood programs like this. Do people come and spend almost 2 months during the academic year at your university? Are they faculty, postdocs, or students?
Dear Excited:
Professors have sabbatical leaves. Many choose to spend it in research workshops/ other universities. There are other reasons why people might have time off. For postdocs it is easier because usually they do not teach. A lot of scientific progress can come out of these workshops and most people in the field consider them to be very useful for their career and to reach their scientific goals.
I have spent the first half of 2001 at the KITP in Santa Barbara (a neat place), with my adviser Tom Banks. As far as I remember, my coursework at the Rutgers PhD program had been finished (defense was on 9/11/2001 at 9:30 am not far from New York City haha) and I just could afford to change the place.
But I believe that grad students, postdocs, and professors may go to such programs even if their schedules are more constrained. KITP is about research work and what people are doing over there is arguably less strictly organized work than what workers are doing in the factories and instructors at average schools but it is still work and very important one.
nice poster, david!