Role of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Λ</mml:mi></mml:math>in the Cosmological Lens Equation
Role of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Λ</mml:mi></mml:math>in the Cosmological Lens Equation
The cosmological constant $\ensuremath{\Lambda}$ affects cosmological gravitational lensing. Effects due to $\ensuremath{\Lambda}$ can be studied in the framework of the Schwarzschild--de Sitter spacetime. Two novel contributions, which cannot be accounted for by a proper use of angular diameter distances, are derived. First, a term $\ensuremath{\delta}{\stackrel{^}{\ensuremath{\alpha}}}_{\ensuremath{\Lambda}}=2mb\ensuremath{\Lambda}/3$ has to be added to …