Office Hours

I can be reached in various ways:

• by e-mail at hhv1@tc.columbia.edu (24/7). I mostly succeed in responding within 48 hours.
• see below for the times when we can meet in person---my preferred mode (while appointments are not necessary, it is best to e-mail me to say that you intend to drop by, and at what time, as I may have stepped out of the office)
• If absolutely necessary, I am also available by appointment via Zoom (set up via e-mail) about every morning, between 9:30 and 11:30, Monday through Thursday.

• in person:
  • Tuesdays: 2 to 4
  • Thursday: 2 to 4

• On Sabbatical
  • I will be unavailable in person
  • I will endeavor to respond from students with whom I am working on their various projects.  This will be best arranged late in the Fall 2026