Whereas there is a well-established standard prescription to compute the spectrum (and higher point functions) of linear cosmological perturbations for single field inflationary models, the same question is much more complicated in multi-field models with canonical or non-canonical kinetic function. Such models are of great interest in the context of string cosmology, too. The study to give a sound theoretical framework on this issue is recently under a rapid developement. However, much work is still required regarding the non-gaussianity, especially the calculation of so-called non-gaussianity parameter f_NL which, observationally, can be extracted from astronomical measurements such as the temperature anisotropies in the cosmic microwave background. This parameter is already constrained observationally, and the constraint is giving some indication for discriminating different inflationary models. Furthermore, given the extremely high accuracy predicted of future observations, it is now crucial to study cosmological perturbation theory beyond the linear approximation in more general framework. Hence we aim to develop non-linear cosmological perturbation theory in such models.

As well as the growth of non-linearities during inflation, the non-linear evolution of density perturbation at the late epoch after the horizon re-entory is also important in order to compare the observational data with the theoretical prediction of various inflation models. At the same time, non-linear evolution of perturbation is discussed also in the context of formation of primordial magnetic field. This workshop covers the wide area of research mentioned above, aiming at finding a breakthrough to the general framework for the non-linear dynamics of cosmological perturbations. We hope that this workshop would help to make further progress in our understanding of the non-linear cosmological perturbations in a systematic way.

The period of this workshop is relatively long. We are planning only two talks per each day besides one special day, April 21 (Tue), to keep a plenty of time for discussions among participants. Since our fund is limitted, we cannot finantially support the participants except for the invited speakers. However, we would like to widely open this valuable opportunity to all researchers who are interested in this topic. Hence, those who participate in this workshop at their own expenses are very welcome, although we may need to restrict the number of participants because of the limitation of the capacity of Yukawa institute. Please contact us at the e-mail address below.

This workshop is held as one of the YITP workshop series and also as a global COE international workshop. The main sponsor of this workshop is Global COE program at Kyoto university, "The Next Generation of Physics, Spun from Universality and Emergence -Developing Independent Researchers to Explore New Frontiers-". This workshop is co-sponsored by The Royal Society.