| 31. | If one varies this with respect to one gets the Adjoint Dirac equation.
|
| 32. | These equations are useful in reducing proofs about adjoint functors to algebraic manipulations.
|
| 33. | The idea of an adjoint functor was formulated by Daniel Kan in 1958.
|
| 34. | This functor is left adjoint to the forgetful functor from groups to sets.
|
| 35. | Thus, we would like a classification of its self-adjoint extensions.
|
| 36. | This functor has a left adjoint which is the integral group ring construction.
|
| 37. | Then the adjoint of is the continuous linear operator satisfying
|
| 38. | Namely, the adjoint of is defined as an operator with the property:
|
| 39. | The two variants are related by an adjoint functor.
|
| 40. | To make the operator self-adjoint a suitable domain must be specified.
|
