public virtual ICollection<Author> Authors { get; set; }

public virtual ICollection<Publication> Publications { get; set; }

Models.Author[] auth = db.Authors.Where(p => p.FullName.ToLower()
    .Contains(searchAuthor).ToLower())).ToArray();

return PartialView("_PublicationList", await db.Publications
    .Where(p => p.Authors.ToList().Contains(auth[0])).ToListAsync());