
Nima
Arkani-Hamed
Our current description of the basic interactions in nature, based
on the standard model of particle physics and general relativity,
is in spectacular agreement with all known experiments. However, it
is almost certainly fundamentally incomplete. In addition to
difficulties associated with strong quantum gravitational effects
at the Planck length, sensible quantum-mechanical theory of
gravity, two striking facts about nature clues suggest that we are
missing a big part of the picture. The extreme weakness of gravity
relative to the other forces, as well as the huge size and flatness
of our observable universe, require absurdly delicate adjustments
of the parameters of the theory. We expect that new physical
principles will be revealed to address these puzzles — the
“hierarchy problem” and the "cosmological constant
problem.” Fortunately, these mysteries are associated with
length scales—the electroweak scale and the Hubble
scale—which will be probed experimentally in the near future
with particle accelerators and cosmological observations. Therefore
theories which address these puzzles are likely to have
experimental consequences that will be checked in the next few
years.
Nima Arkani-Hamed’s research in theoretical physics is
driven by attempting to address these mysteries. Much of his work
has centered around addressing the hierarchy problem. Together with
Savas Dimopoulos and Gia Dvali, he suggested that the extreme
weakness of gravity can be attributed to the existence of large
extra dimensions of space, perhaps as large as 100 microns in size,
with the scale of quantum gravity lowered to the electroweak scale.
This opens up the possibility that quantum gravitational effects
can be probed at accelerators and even in table-top experiments. In
a different direction, together with Andy Cohen and Howard Georgi
he has constructed models where (non-gravitational) extra
dimensions are generated dynamically from purely four-dimensional
models. This has also led to new approaches to the hierarchy
problem. He has also investigated the possibility that gravity is
modified at large distances and times in an effort to address
various cosmological problems. Most recently, together with
Dimopoulos, he has explored the possibility that the fine-tunings
for the cosmological constant and hierarchy problems find a common
explanation within a huge landscape of possible low-energy worlds
that may exist in string theory, leading to a novel proposal for
"split" supersymmetry at the large hadron collider.
Recent Talks:
Selected
Publications:
- N. Arkani-Hamed, L. Motl, A. Nicolis, C. Vafa, "The String
landscape, black holes and gravity as the weakest force,"
HUTP-05-A0057, Jan 2006. hep-th/0601001
- N. Arkani-Hamed, S. Dimopoulos, S. Kachru, " Predictive
landscapes and new physics at a TeV," SLAC-PUB-10928,
HUTP-05-A0001, SU-ITP-04-44, Jan 2005. hep-th/0501082
- N. Arkani-Hamed and S. Dimopoulos, "Supersymmetric Unification
Without Low Energy Supersymmetry and Signatures for Fine-Tuning at
the LHC," hep-th/0405159
- N. Arkani-Hamed, H.-C. Cheng, M. A. Luty, and S. Mukohyama,
"Ghost Condensation and a Consistent Infrared Modification of
Gravity," JHEP 0405, 074 (2004) hep-th/0312099
- N. Arkani-Hamed, A. G. Cohen, and H. Georgi, "Electroweak
Symmetry Breaking from Dimensional Deconstruction," Phys. Lett. B 513, 232 (2002). hep-ph0105239
- N. Arkani-Hamed, A. G. Cohen, and H. Georgi, "(De)Constructing
Dimensions," Phys. Rev. Lett. 86, 4757
(2001). hep-th0104005
- N. Arkani-Hamed, S. Dimopoulos, and G. Dvali, "Phenomenology,
Astrophysics and Cosmology of Theories with Sub-Millimeter
Dimensions and TeV Scale Quantum Gravity," Phys. Rev D 59, 086004 (1999). hep-ph9807344
- I. Antoniadis, N. Arkani-Hamed, S. Dimopoulos, and G. Dvali,
"New Dimensions at a Millimeter to a Fermi and Superstrings at a
TeV," Phys. Lett. B 436, 57 (1998).
hep-ph9804398
- N. Arkani-Hamed, S. Dimopoulos, and G. Dvali, "The Hierarchy
Problem and New Dimensions at a Millimeter," Phys. Lett. B 429, 263 (1998). hep-ph9803315
Contact
information:
Academic Assistant:
Michele Turansick
Institute for Advanced Study
School of Natural Sciences
Einstein Drive
Princeton, NJ 08540
Phone: 609-734-8058
Fax: 609-924-7592
E-mail: mat at ias.edu
Back to
Natural Sciences Home Page
Address questions and comments about this server to webmaster@sns.ias.edu