Nuclear and High-Energy Astrophysics

There has never been a more exciting time in the overlapping areas of nuclear physics, particle physics and relativistic astrophysics than today. Orbiting observatories such as the Hubble Space Telescope, Rossi X-ray Timing Explorer (RXTE), Chandra X-ray satellite, and the X-ray Multi Mirror Mission (XMM) have extended our vision tremendously, allowing us to see vistas with an unprecedented clarity and angular resolution that previously were only imagined, enabling astrophysicists for the first time ever to perform detailed studies of large samples of galactic and extragalactic objects. On the Earth, radio telescopes (e.g., Arecibo, Green Bank, Parkes, VLA) and instruments using adaptive optics and other revolutionary techniques have exceeded previous expectations of what can be accomplished from the ground. The gravitational wave detectors LIGO, LISA VIRGO, and Geo-600 are opening up a window for the detection of gravitational waves emitted from compact stellar objects such as neutron stars and black holes. Together with new experimental forefront facilities like ISAC, ORLaND and RIA, these detectors provide direct, quantitative physical insight into nucleosynthesis, supernova dynamics, accreting compact objects, cosmic-ray acceleration, and pair-production in high energy sources which reinforce the urgent need for a strong and continuous feedback from nuclear and particle theory and theoretical astrophysics. In my lectures, I shall concentrate on three selected topics, which range from the behavior of superdense stellar matter, to general relativistic stellar models, to strange quark stars and possible signals of quark matter in neutron stars.Comment: 52 pages, 43 figures; to appear in the Proceedings of the VIII International Workshop on Hadron Physics, April 14-19, 2002, Rio Grande do Sul, Brazi

On the category of Euclidean configuration spaces and associated fibrations

We calculate the Lusternik-Schnirelmann category of the k-th ordered configuration spaces F(R^n,k) of R^n and give bounds for the category of the corresponding unordered configuration spaces B(R^n,k) and the sectional category of the fibrations pi^n_k: F(R^n,k) --> B(R^n,k). We show that secat(pi^n_k) can be expressed in terms of subspace category. In many cases, eg, if n is a power of 2, we determine cat(B(R^n,k)) and secat(pi^n_k) precisely.Comment: This is the version published by Geometry & Topology Monographs on 19 March 200

Shortcomings of learning design approaches and a possible way out

Shifting away from traditional instructional design to younger research streams like personalized, workflow-based or collaborative e-learning, learning design (LD) has become an important issue in the field of technology-enhanced learning. Nevertheless, current LD approaches turn out to be rather unhandy or costly in teaching and research practice. In this paper, we discuss these shortcomings and propose an alternative solution approach which is based on a web application mashup, learner interactions, and a semantic layer for tool recommendations. As the evaluation of our first prototype is in progress, we can not highlight first experiences, but outline benefits and possible application scenarios in this position paper

R(p,q)- analogs of discrete distributions: general formalism and application

In this paper, we define and discuss $\mathcal{R}(p,q)$- deformations of basic univariate discrete distributions of the probability theory. We mainly focus on binomial, Euler, P\'olya and inverse P\'olya distributions. We discuss relevant $\mathcal{R}(p,q)-$ deformed factorial moments of a random variable, and establish associated expressions of mean and variance. Futhermore, we derive a recursion relation for the probability distributions. Then, we apply the same approach to build main distributional properties characterizing the generalized $q-$ Quesne quantum algebra, used in physics. Other known results in the literature are also recovered as particular cases

R(p,q)-deformed conformal Virasoro algebra

This paper addresses an R(p,q)-deformed conformal Virasoro algebra with an arbitrary conformal dimension Delta. Wellknown deformations constructed in the literature are deduced as particular cases. Then, the special case of the conformal dimension Delta=1 is elucidated for its interesting properties. The R(p,q)-KdV equation, associated with the deformed Virasoro algebra, is also derived and discussed. Finally, the (p,q)-deformed energy-momentum tensor, consistent with the central extension term, is computed and analyzed