Buongiorno, segnalo questo seminario di Michele Benzi in SNS, e ne approfitto per ricordare anche quello di Liqun Qi di lunedì prossimo:
Speaker: Liqun Qi, The Hong Kong Polytechnic University, Department of Applied Mathematics
Title: Tensor Analysis: Spectral Theory and Special Tensors
Room: Sala Riunioni, Dipartimento di Matematica
Time: Monday, June 12, 11:00
-------- Forwarded Message -------- Subject: [Settimanale] avviso Seminario di Matematica prof. Michele Benzi (8.06.2017) Date: Mon, 5 Jun 2017 10:13:39 +0200 From: Valeria Giuliani valeria.giuliani@sns.it
SEMINARIO DI MATEMATICA
Giovedì 8 giugno 2017
ore 11:00
_Scuola Normale Superiore_
Pisa
Aula Marie Curie
*_ _*
* **Michele Benzi***
/(Samuel Candler Dobbs Professor - Emory University)/
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terrà un seminario dal titolo:
*“**Decay properties of matrix functions with applications to electronic structure computations**”***
* *
*Abstract:*
/Functions of matrices, such as the matrix exponential or the square root, arise in a number of scientific and technical applications, ranging from quantum mechanical computations to the structural analysis of complex graphs and networks. The actual numerical evaluation of functions of large and sparse matrices can be quite challenging, and much effort has been devoted to this problem in recent years. An important property that is frequently exhibited by analytic functions of large and sparse matrices is the rapid off-diagonal decay of the matrix entries; careful exploitation of this property can lead to algorithms with optimal computational complexity (this means that the cost scales linearly with the dimension of the problem).///
/In this talk I will present some rigorous estimates on the size of the off-diagonal entries of analytic matrix functions. As a special case, the theory yields a proof of the exponential decay, or "localization", of the density matrix (spectral projector) arising in electronic structure computations for gapped systems, a classical problem in solid state physics and quantum chemistry. In addition to giving a precise mathematical form to W. Kohn's notion of "nearsightedness of electronic matter", these estimates provide a sound basis for the development of linear scaling methods./*//*
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Tutti gli interessati sono invitati a partecipare.
Classe di Scienze Matematiche e Naturali
Valeria Giuliani Scuola Normale Superiore Servizio alla Didattica e Allievi tel. 050 509260 Piazza dei Cavalieri, 7 56126 Pisa E-mail: valeria.giuliani@sns.it mailto:valeria.giuliani@sns.it E-mail: classi@sns.it mailto:classi@sns.it