| ower bound on Λ |
| a href="/encyclopedia/1988" title="1988">1988 | -50 |
| a href="/encyclopedia/1991" title="1991">1991 | -5 |
| a href="/encyclopedia/1990" title="1990">1990 | -0.385 |
| a href="/encyclopedia/1994" title="1994">1994 | -4.379 · 10 -6 |
| a href="/encyclopedia/1993" title="1993">1993 | -5.895 · 10 -9 |
| a href="/encyclopedia/2000" title="2000">2000 | -2.7 · 10 -9 |