I am a international undergraduate student pursuing mechanical engineering. I want to shift to physics and so I am considering of applying to graduate programs in hep-th/astroparticle physics this year. I have not been able to complete the necessary courses in physics .But I have a good research profile in physics with two internships, one in quantum mechanics and another in hep-th. I have one published paper, three papers in the physics arxiv. I think I will be able to publish or at least write another paper before I apply . With good GRE and PGRE scores , very good letters of recommendation, average grades which universities in the US should I aim for ??