Friday 24 May 2024 |
Events for day: Wednesday 22 May 2024 |
13:30 - 15:00 A magnetic massive star has experienced a stellar merger (Canceled) School ASTRONOMY Massive stars (those ?8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7% of massive stars have observed magnetic fields, the origin of which is debated. We used multi- epoch interferometric and spectroscopic observations to characterize HD 148937, a binary system of two massive stars. We found that only one star is magnetic and that it appears younger than its companion. The system properties and a surrounding bipolar nebula can be reproduced with a model in which two stars merged (in a previous triple system) to pr ... 14:00 - 15:00 Combinatorics and Computing Weekly Seminar Partitions into Pairs with Prescribed Differences School MATHEMATICS Consider the following two general questions: -For an Abelian group $A$ of order $2n$ and nonzero elements $d_1, ldots, d_n$ of $A$, is it always possible to partition $A$ into pairs such that the difference between the two elements of the $i$th pair is equal to $d_i$? -For an Abelian group $A$ of order $2n+1$ and nonzero elements $d_1, ldots, d_n$ of $A$, is it always possible to partition $Asetminus{0}$ into pairs such that the difference between the two elements of the $i$th pair is equal to $d_i$? In this ta ... 16:00 - 17:00 Mathematics Colloquium Weak Arithmetic and Galois Theory School MATHEMATICS In this lecture, we shall talk about Arithmetic from a Logical point view and introduce a related scheme of first-order axioms in the language of Arithmetic, called Open Induction (OI) and show how the problem of characterising the logical hierarchy of subsystems of OI, naturally leads to Galois Theory. Venue: Niavaran, Lecture Hall 1 ... |