Seminar on Complex Geometry and Mathematical Physics

 

	日時：	2005年4月16日(土)13時30分から
	場所：	数理解析研究所 202号室
	講演者：	阿部 拓郎 氏（京大・理）
	題目：	Splitting problems of sheaves on projective spaces

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Seminar on Complex Geometry, 2005

	Speaker:	Prof. David Bessis
	Title:	Topology of Complex Reflection Discriminants
	Date:	March 10th (Thu) 13:30 -, Room 402, RIMS March 18th (Fri) 13:30 -
	Place:	RIMS (to be announced)
	Date: March 5th (Sat.) 13:00 - 17:00 (2 talks),        18:00 - (We will have dinner together with speakers)
	Place: RIMS Seminar room 202
	Schedule: 13:30 - 15:00 Speaker: Prof. David Bessis Title: Topology of Complex Reflection Discriminants
	15:00 - 15:30 Break
	15:30 - 17:00 Speaker: Prof. Pierre Cartier                  (CNRS/Jussieu and IHES , France) Title: On the Dimensional Regularisation Method in Quantum Field Theory and the Bernstein Polynomial Abstract: The method of dimensional renormalisation is widely used in Quantum Field Theory , especially because it is consistent with gauge invariance . In an effort to dispel the magics of a space-time with a nonintegral dimension , we propose a new viewpoiint , valid for both bosonic AND fermionic fields . We use a functional transformation , introduced around 1960 by Schwinger and then developed by Symanzik . The "bare" scattering amplitude is expressed as an integral over the Schwinger $alpha$ parameters , diverging when these parameters , of the nature of a squared-length , approach 0 . We remark that the space-time dimension D appears explicitly in one place only , as the exponent of a rational function in a certain integral . The analytic continuation with respect to D can be achieved by the method of Gelfand-Bernstein . The so-called b-polynomial , and the geometry of the singular locus control the substraction procedure necessary to regularize the divergent amplitudes . The method is perfectly general , but has to be carried explicitly in any model .
	Speaker:	Professor David Bessis (ENS/RIMS)
	Title:	Topology of Complex Reflection Discriminants
	Room:	RIMS 202
	Date:	February 26th (Sat) 10:30 - 12:00   Lecture
	Speaker:	Professor David Bessis (ENS/RIMS)
	Title:	Topology of Complex Reflection Discriminants
	Date:	February 12th (Sat), February 19th (Sat)
	Room:	RIMS 202
	Schedule:	13:30 - 15:30   Lecture
		15:30 - 16:00   Break
		16:00 -             Discussion

Research Institute for Mathematical Sciences, Kyoto University

Atsushi Takahashi