### Instruction:

Extract the cause and effect entities from the following sentence:
Several independent observations indicate that the cosmological expansion began to accelerate when the universe was around half of its present age

### Assistant:

VARIABLE: the universe
CONDITION: was around half of its present age
EFFECT_1: the cosmological expansion began to accelerate
KEYWORD: when
CAUSE_1: the universe was around half of its present age
NOT_RELEVANT: Several independent observations indicate that

