Hot fragmentation of nuclei

Today, we have a variety of reactions at hand that can be used to multi-fragment nuclei. In many of these reactions even several sources of fragments can be discerned and characterized. There is overwhelming evidence that these sources of fragments are hot. It is already less clear whether heat by itself is sufficient to initiate the fragment decay. What causes fragmentation, and when and how are the fragments (pre)formed? These questions have remained as much a challenge as the complementary class of questions to which they are related: What observations derive their significance from the liquid-gas phase behavior of extended nuclear matter? And, can we observe a phase transition in finite nuclei? Recent developments, largely coming from complex analyses of data sets measured in 4-pi-type experiments as well as from calculations based on advanced theoretical concepts, will be discussed.Comment: 13 pages, with 8 included figures; To appear in the proceedings of the NN 2000 conference; Also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.htm

Isometry and Automorphisms of Constant Dimension Codes

We define linear and semilinear isometry for general subspace codes, used for random network coding. Furthermore, some results on isometry classes and automorphism groups of known constant dimension code constructions are derived

Message Encoding for Spread and Orbit Codes

Spread codes and orbit codes are special families of constant dimension subspace codes. These codes have been well-studied for their error correction capability and transmission rate, but the question of how to encode messages has not been investigated. In this work we show how the message space can be chosen for a given code and how message en- and decoding can be done.Comment: Submitted to IEEE International Symposium on Information Theory 201

Pl\"ucker Embedding of Cyclic Orbit Codes

Cyclic orbit codes are a family of constant dimension codes used for random network coding. We investigate the Pl\"ucker embedding of these codes and show how to efficiently compute the Grassmann coordinates of the code words.Comment: to appear in Proceedings of the 20th International Symposium on Mathematical Theory of Networks and Systems 2012, Melbourne, Australi

Thermodynamic Variables from Spectator Decay

New results for the masses, excitation energies, temperatures, and densities of excited spectator systems at breakup are presented. They were obtained in two recent experiments with the ALADIN spectrometer at SIS in which reactions of Au-197 on Au-197 in the regime of relativistic energies up to 1 GeV per nucleon were studied. The methods used to extract these thermodynamic variables are discussed.Comment: 17 pages, TeX with 10 included figures; To appear in the proceedings of the 14th Winter Workshop on Nuclear Dynamics, Snowbird, Utah, January 31 - February 7, 1998; also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.htm