6.1 The Hawking energy
  6.1.1 The definition
  6.1.2 Hawking energy for spheres
  6.1.3 Positivity and monotonicity properties
  6.1.4 Two generalizations
 6.2 The Geroch energy
  6.2.1 The definition
  6.2.2 Monotonicity properties
 6.3 The Hayward energy