The cosmological constant is important for at least two reasons.

1. Our universe is currently asymptotically evolving towards a universe where a constant energy density dominates the total energy density. The cosmological constant can be interpreted as exactly this. Therefore, analysis of the current state of our universe relies heavily on the concept of a cosmological constant, even if we don't know how it arises.
2. inflationary theory, which has recently received strong experimental support from the BICEP2 experiment, asserts that the early universe went through a de Sitter-like epoch during which it underwent exponential expansion, driven by a large (quasi-)constant energy density (i.e. effective cosmological constant.

Thus, the cosmological constant is acutely relevant to both the past and future of our universe. This is an extremely condensed account and could be expanded immensely. It is also interesting for historical reason, and because 'why not?'.

The cosmological constant is important for at least two reasons.

1. Our universe is currently asymptotically evolving towards a universe where a constant energy density dominates the total energy density. The cosmological constant can be interpreted as exactly this. Therefore, analysis of the current state of our universe relies heavily on the concept of a cosmological constant, even if we don't know how it arises.
2. inflationary theory, which has recently received strong experimental support from the BICEP2 experiment, asserts that the early universe went through a de Sitter-like epoch during which it underwent exponential expansion, driven by a large (quasi-)constant energy density (i.e. effective cosmological constant).

Thus, the cosmological constant is acutely relevant to both the past and future of our universe. This is an extremely condensed account and could be expanded immensely. It is also interesting for historical reason, and because 'why not?'.

The cosmological constant is important for at least two reasons.

1. Our universe is currently asymptotically evolving towards a universe where a constant energy density dominates the total energy density. The cosmological constant can be interpreted as exactly this. Therefore, analysis of the current state of our universe relies heavily on the concept of a cosmological constant, even if we don't know how it arises.
2. inflationary theory, which has recently received strong experimental support from the BICEP2 experiment, asserts that the early universe went through a de Sitter-like epoch during which it underwent exponential expansion, driven by a large (quasi-)constant energy density (i.e. effective cosmological constant.

Thus, the cosmological constant is acutely relevant to both the past and future of our universe.

The cosmological constant is important for at least two reasons.

1. Our universe is currently asymptotically evolving towards a universe where a constant energy density dominates the total energy density. The cosmological constant can be interpreted as exactly this. Therefore, analysis of the current state of our universe relies heavily on the concept of a cosmological constant, even if we don't know how it arises.
2. inflationary theory, which has recently received strong experimental support from the BICEP2 experiment, asserts that the early universe went through a de Sitter-like epoch during which it underwent exponential expansion, driven by a large (quasi-)constant energy density (i.e. effective cosmological constant.

Thus, the cosmological constant is acutely relevant to both the past and future of our universe. This is an extremely condensed account and could be expanded immensely. It is also interesting for historical reason, and because 'why not?'.