Four more years

Four and more

We isolate several large classes of definable proper forcings and show how they include many partial orderings used in practice.

RoboCupJunior - Four Years Later

In this paper, we report on the status of the RoboCupJunior league, four years after it was founded. Since its inception in 2000, we have been surveying and/or interviewing students and mentors who participate in the international event. Here we present a high-level overview of this data. We discuss demographics of participants, characteristics of preparation and educational value. We highlight...

The First Four Billion Years

More on four-dimensional extremal black holes.

We consider an embedding of the extremal four-dimensional Reissner-Nordström black hole into type IIB string theory. The equivalent type IIB configuration, in the D-brane weak-coupling picture, is a bound state of D1and D5-branes threaded by fundamental type IIB strings. The bound state involves also a NSNS solitonic 5-brane, mimicking the role of the Kaluza-Klein magnetic monopole. The statist...

Theories in More than Four Dimensions ∗

Particle physics models where there are large hidden extra dimensions are currently on the focus of an intense activity. The main reason is that these large extra dimensions may come with a TeV scale for quantum gravity (or string theory) which leads to a plethora of new observable phenomena in colliders as well in other areas of particle physics. Those new dimensions could be as large as milli...