Difference between revisions of "Differential Geometry II - 2020"

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(Niko, 6.8.2020)
(Niko, 6.8.2020)
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* Gauss equations
 
* Gauss equations
Def: 2nd FF \(h(X,Y)\) and \(h_N(X,Y)\) (Mind: what are relations of LC-connections and metric in \(M\) and \(\bar{M}\)  
+
Def: 2nd FF \(h(X,Y)\) and \(h_N(X,Y)\) (Mind: How are the LC-connections \(D,\bar{D}\) and metrics \(g,\bar{g}\) of \(M\) and \(\bar{M}\) related)
  
 
Proof: Show symmetry of (\h\)
 
Proof: Show symmetry of (\h\)

Revision as of 09:20, 10 August 2020

Niko, 6.8.2020

  • Levi-Civita Connection:

Def: torsion-free and compatible with metric

Koszul-Formula

Uniqueness of L-C-Connection

(Mentioned case of Lie-group with bi-invariant Riem. metric and left-invariant vector fields, but I didn't remember and we just skipped that)

  • Rauch comparison theorem

Def: Jacobi Field (and geometric interpretation)

Thm 3.18: Statement

  • Gauss equations

Def: 2nd FF \(h(X,Y)\) and \(h_N(X,Y)\) (Mind: How are the LC-connections \(D,\bar{D}\) and metrics \(g,\bar{g}\) of \(M\) and \(\bar{M}\) related)

Proof: Show symmetry of (\h\)

State Gauss equations

State in terms of \(sec\) instead of \(R\)

  • Hadamard, Cartan

State theorem 4.12

Claim in proof: \(sec\leq0\) implies no conjugate points. (This was an exercise in script)

Prove claim.