לוח שנה משולב

In the LCDM cosmological model, dark matter halos and light-emitting
galaxies form hierarchically. The halos and galaxies grow via mergers of
lower mass objects, as well as by direct accretion of material from the
intergalactic medium. I will describe my analysis of the cosmological, dark-matter-only, Millennium and Millennium-II Simulations for a quantitative
understanding of the various growth modes. I show that the role of
non-merger, "smooth", accretion onto halos is significant compared with
major and/or minor mergers. The theoretical results are in good agreement
with recent observations of UV-/optically selected massive star-forming
galaxies at z~2 that indicate that the baryonic mass assembly and star
formation history are dominated by continuous rapid accretion of gas and
internal secular evolution. I will also present high-resolution,
"zoom-in", cosmological N-body/SPH simulations that produce star-forming
disks similar to the observed z~2 galaxies, and discuss the feedback
mechanisms required to reproduce the observations.

Quantum Control (QC), sometimes referred to as Optimal Control or Coherent
Control, aims at altering the course of quantum dynamics phenomena for specific
target realizations, typically by means of closed-loop, adaptively shaped laser pulses.
This field has experienced a rapid increase of interest during recent years, in parallel to
the technological developments of ultrafast laser pulse shaping capabilities, that made
it possible to turn this early-days dream into reality. Quantum Control Experiments
(QCE), the topic of this talk, consider the realization of QC in the laboratory, where the
objective function evaluation cannot be done through a computer simulation, but rather
requires the execution of a real-world experiment. The optimization task of QC systems
typically introduces many challenges to the search (e.g., high-dimensionality, noise,
constraints handling, to name a few), and thus offers a rich domain for the development
and application of specialized optimizers. This talk will present the main characteristics
of QCE laboratory optimization, and particularly practical issues such as optimizer efficiency,
robustness of attained pulses, landscape exploration, and Pareto optimization
of multiple objectives. Toward that end, it will discuss a case-study with a great potential
for future applications, namely Optimal Dynamic Discrimination (ODD), where
extremely short shaped pulses allow for the differentiation of similar molecules. It will
also review a specific class of derandomized search heuristics which are especially attractive
for such tasks.

Active space experiments study plasma processes induced by different energy releases in space (plasma clouds, beams of energetic particles, powerful radio-emissions). High altitude nuclear explosions can be considered from this point of view. A number of effects of geo- and astrophysical importance were observed during the space tests of nuclear weapon conducted in 50s – early 60s. Development of Rayleigh-Taylor instability, diamagnetic cavity formation, artificial aurora are considered. There is certain evidence that transient luminous events (sprites) were observed during the Starfish test in 1962.