Closed subset (with respect to weak topology)?

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SUMMARY

The discussion centers on whether the space LG, defined as the base point preserving loops in a Hilbert manifold, is a closed subset of L^2[0, 2pi] with respect to the weak topology. LG is represented as { f : S^1 -> G | f(0)=1 }, where G is a connected, simply connected Lie group. The weak topology on LG is derived from the weak topology on L^2[0, 2pi], characterized by the basis of neighborhoods defined by the functional F in X*. The inquiry focuses on the weak continuity of the embedding of LG into L^2[0, 2pi].

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  • Understanding of Hilbert manifolds and their properties
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  • Knowledge of L^2 spaces, specifically L^2[0, 2pi]
  • Basic concepts of nets in topology
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Mathematicians, particularly those specializing in functional analysis, topology, and differential geometry, will benefit from this discussion. It is also relevant for researchers working on the properties of Hilbert manifolds and their applications in theoretical physics.

HMY
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Let LG be the base point preserving loops (it's a Hilbert manifold).
So LG = { f : S^1 -> G s.t. f(0)=1 } where G is a connected, simply connected Lie group.

LG is embedded into the (vector space) Hilbert space L^2[0, 2pi]
given by f |--> g(t) = f '(t)f(t)^-1


Is LG a closed subset of L^2[0,2pi] with respect to the weak topology?
(or is the embedding weakly continuous)?



I figured out the weak topology (reminder here):

Let X = L^2[0,2pi]
Let U(F,b) := { x in X | |F(x)| < b } where b is in R & F is in X^*
So {U(F,b)} are a basis of a neighbourhood of 0 in X.
Thus {x + U(F,b) } are a basis of a neighbourhood of x in X.
ie. the neighbourhoods of an arbitrary x in X are precisely the translates x + W of
neighbourhoods W of 0

So the weak topology on LG is just the subset topology coming from the weak topology
defined on X.
 
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Nets give a nice characterization of the weak topology...
 
dvs said:
Nets give a nice characterization of the weak topology...


What would this be?

I'm not fluent with nets (yet) but if this characterization is nice enough then it is perhaps easier for me to work with it here, than what I was trying before.
 

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