Is SR a subset of GR ?

[Jacques]

Or is SR a special case of GR where acceleration is equal to zero ?

[insane_alien]

yup. SR is the special case of general relativity where there is no acceleration. you can use either in that case and you will get the same answers.

[Jacques]

Thanks for your answer

[swansont]

Keep in mind that someone at rest in a gravitational field is considered to be in an accelerating reference frame; it's indistinguishable from accelerating at g somewhere far from a gravitational field. Someone in freefall is not.

[Dims]

But what do you mean by subset?

 

The oweral set af cases, including large accelerations and gravitational fields, described by GR. The subset of this set, where accelerations and/or gravitational fields are not large, described by SR.

 

In this sense, the SR is a subset of GR.