Since arriving in the District more than a year ago, Erica Rebollar has been one of the most intriguing additions to the city’s dance scene. A fluid dancer whose choreography tends towards the specific, Rebollar has quickly established herself here. This fall is a big one for her: She’ll be performing in an annual dance sampler in October and setting her choreography on a local company in November. But the best time to catch her company, Rebollar Dance, is December, when the ensemble will be showing its latest full-length piece, Space Junk, an exploration of inner and outer realms.