My name is Rachel A. Rosen, and I'm an associate
professor at Columbia University in the department
of physics.
As a kid, I was sort of enamored with Sally
Ride. So I saw her on TV when I was  maybe
even on some PBS program or something when I was a kid, and was really excited about
what she was doing.
The focus of my research is on quantum field
theory and applications of quantum field theory
to particle physics and gravity, and occasionally
to condensed matter systems as well.
The black hole information paradox is sort
of an outstanding problem. If you threw a
dictionary into a fire, even if it burned
up, if somehow you could collect everything
that was emitted, you could reconstruct the
dictionary. But it's an open question with black holes.
I've been looking at, from particle
physics point of view, alternative theories
of gravity. So one in particular goes by the
name of massive gravity, and it's the theory
in which the graviton, the particle that conveys
the gravitational force, has a small mass.
And so, this is in contrast to Einstein's
general relativity, where the particle that
conveys the gravitational force is massless.
So one thing that I'm very interested in is
what do black holes look like in this alternative
theory of gravity? So one of the main things
that seems to happen is that either you have
to give up this assumption of time independence
and your black holes have to have some time
dependence, or maybe you have to give up the
notion instead of spherical symmetry, and
black holes and massive gravity might inherently
have to be rotating, something like that.
There's the question of what's the correct
gravitational theory, at incredibly short
distances where quantum effects become important,
so this is what string theory addresses. The
third sort of open question related to gravity
is the explanation of the cosmic expansion
of the universe. So why is the cosmic expansion
accelerating in particular? And so, it's possible,
it's likely that this is just some vacuum
energy, some cosmological constant, but in
which case, you really want to understand
what the value of the cosmological constant
is. And so, all three of these problems are
related to gravity.
Day to day, I have a lot of different responsibilities,
teaching and meeting with students, and writing
grant applications, and then the actual part
that really motivates me, is the research
part as well. And so, that often involves
anything from meeting with collaborators and
discussing new ideas that we have, to looking
for papers and reading papers that might be
related to what we're interested in.
I think you can use mathematics to explain
actual phenomena that you see in the real
world. That's always felt kind of magical
to me. By studying quantum field theory and
particle physics and gravity, you're sort
of getting at the most fundamental questions
about our universe.
