Knot at Lunch, November 7, 2007 - Revision history

Drorbn at 16:37, 7 November 2007

2007-11-07T16:37:26Z

← Older revision		Revision as of 12:37, 7 November 2007
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	* Relative expansions.		* Relative expansions.
	* Functorial expansions.		* Functorial expansions.
			* Expansions for other algebraic structures.

	===Note===		===Note===

Drorbn at 16:35, 7 November 2007

2007-11-07T16:35:38Z

← Older revision		Revision as of 12:35, 7 November 2007
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	* Relative expansions.		* Relative expansions.
	* Functorial expansions.		* Functorial expansions.

			===Note===
			If <math>\sigma_j</math> denote the standard generators of the (non-pure) braid group <math>B_n</math> then the pure braid group <math>PB_n</math> is generated by elements <math>x_{ij}</math> with <math>i<j</math> and
			{{Equation*\|<math>x_{ij}=(\sigma_{j-2}\cdots\sigma_i)^{-1}\sigma_{j-2}^2(\sigma_{j-2}\cdots\sigma_i)</math>}}
			with relations (always <math>i<j<k<l</math>):
			{{Equation*\|<math>[a_{ijk},x_{ij}]=[a_{ijk},x_{ik}]=[a_{ijk},x_{jk}]=1</math> where <math>a_{ijk}:=x_{ij}x_{ik}x_{jk}</math>}}
			and
			{{Equation*\|<math>[x_{ij},x_{kl}]=[x_{il},x_{jk}]=[x_{ik},x_{ij}^{-1}x_{jl}x_{ij}]=1</math>.}}

Drorbn: /* The Agenda */

2007-11-06T14:19:23Z

The Agenda

← Older revision		Revision as of 10:19, 6 November 2007
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	==The Agenda==		==The Agenda==
	* Definition of "~~Expansion~~".		* Definition of "an expansion".
	* Solving equations in groups.		* Solving equations in groups.
	* Examples: <math>{\mathbb Z}</math>, <math>{\mathbb Z}^n</math>, <math>F_n</math>, <math>PB_n</math>, and <math>B_n</math>.		* Examples: <math>{\mathbb Z}</math>, <math>{\mathbb Z}^n</math>, <math>F_n</math>, <math>PB_n</math>, and <math>B_n</math>.

Drorbn at 14:18, 6 November 2007

2007-11-06T14:18:58Z

← Older revision		Revision as of 10:18, 6 November 2007
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	{{KAL/Navigation}}		{{KAL/Navigation}}

	==Invitation==		==Invitation==

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	We will have our next fall lunch on Wednesday November 7, at 12 noon, '''not''' in our usual place, but instead at the department "meeting room", Bahen 6290B (the little room by the mail room, entrance from the administrative offices)		We will have our next fall lunch on Wednesday November 7, at 12 noon, '''not''' in our usual place, but instead at the department "meeting room", Bahen 6290B (the little room by the mail room, entrance from the administrative offices)

	As always, please bring brown-bag lunch and fresh ideas. The agenda: I will lead an informal discussion of "Expansions for ~~groups~~".		As always, please bring brown-bag lunch and fresh ideas. The agenda: I will lead an informal discussion of "Expansions for Groups".

	As always, if you know anyone I should add to this mailing list or if you wish to be removed from this mailing list please let me know. To prevent junk accumulation in mailboxes, I will actively remove inactive people unless they request otherwise.		As always, if you know anyone I should add to this mailing list or if you wish to be removed from this mailing list please let me know. To prevent junk accumulation in mailboxes, I will actively remove inactive people unless they request otherwise.
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	Dror.		Dror.

			==The Agenda==
			* Definition of "Expansion".
			* Solving equations in groups.
			* Examples: <math>{\mathbb Z}</math>, <math>{\mathbb Z}^n</math>, <math>F_n</math>, <math>PB_n</math>, and <math>B_n</math>.
			* Relative expansions.
			* Functorial expansions.

Drorbn at 19:10, 5 November 2007

2007-11-05T19:10:47Z

New page

{{KAL/Navigation}}

==Invitation==

Dear Knot at Lunch People,

We will have our next fall lunch on Wednesday November 7, at 12 noon, '''not''' in our usual place, but instead at the department "meeting room", Bahen 6290B (the little room by the mail room, entrance from the administrative offices)

As always, please bring brown-bag lunch and fresh ideas. The agenda: I will lead an informal discussion of "Expansions for groups".

As always, if you know anyone I should add to this mailing list or if you wish to be removed from this mailing list please let me know. To prevent junk accumulation in mailboxes, I will actively remove inactive people unless they request otherwise.

Best,

Dror.