1,346 research outputs found
Deconstructing graviphoton from mass-deformed ABJM
Mass-deformed ABJM theory has a maximally supersymmetric fuzzy two-sphere
vacuum solution where the scalar fields are proportional to the TGRVV matrices.
We construct these matrices using Schwinger oscillators. This shows that the
ABJM gauge group that corresponds to the fuzzy two-sphere geometry is
. We deconstruct the graviphoton term in the D4 brane
theory. The normalization of this term is fixed by topological reasons. This
gives us the correct normalization of the deconstructed U(1) gauge field and
fixes the Yang -Mills coupling constant to the value which corresponds to M5
brane compactified on \mb{R}^ {1,2} \times S^3/{\mb{Z}_k}. The graviphoton
term also enable us to show that the zero mode contributions to the partition
functions for the D4 and the M5 brane agree.Comment: 26 page
Conditional statistics of electron transport in interacting nanoscale conductors
Interactions between nanoscale semiconductor structures form the basis for
charge detectors in the solid state. Recent experimental advances have
demonstrated the on-chip detection of single electron transport through a
quantum dot (QD). The discreteness of charge in units of e leads to intrinsic
fluctuations in the electrical current, known as shot noise. To measure these
single-electron fluctuations a nearby coherent conductor, called a quantum
point contact (QPC), interacts with the QD and acts as a detector. An important
property of the QPC charge detector is noninvasiveness: the system physically
affects the detector, not visa-versa. Here we predict that even for ideal
noninvasive detectors such as the QPC, when a particular detector result is
observed, the system suffers an informational backaction, radically altering
the statistics of transport through the QD as compared to the unconditional
shot noise. We develop a theoretical model to make predictions about the joint
current probability distributions and conditional transport statistics. The
experimental findings reported here demonstrate the reality of informational
backaction in nanoscale systems as well as a variety of new effects, such as
conditional noise enhancement, which are in essentially perfect agreement with
our model calculations. This type of switching telegraph process occurs
abundantly in nature, indicating that these results are applicable to a wide
variety of systems.Comment: 16 pages, 3 figures, to appear in Nature Physic
Probing AdS4/CFT3 proposals beyond chiral rings
We calculate the superconformal Witten index for the Chern-Simons-matter
theory which was proposed to describe multiple M2-branes on . We
consider a variant of this model, which exhibits explicit N=3 supersymmetry and
has the advantage of not having an exotic branch of the moduli space. At ,
we compare the index with that from the proposed gravity dual and find a
disagreement.Comment: references added; introduction modifie
Constraining Maximally Supersymmetric Membrane Actions
We study the recent construction of maximally supersymmetric field theory
Lagrangians in three spacetime dimensions that are based on algebras with a
triple product. Assuming that the algebra has a positive definite metric
compatible with the triple product, we prove that the only non-trivial examples
are either the well known case based on a four dimensional algebra or direct
sums thereof.Comment: 11 pages, very minor changes. Reference added. Version to be
published in JHE
M2-branes on M-folds
We argue that the moduli space for the Bagger-Lambert A_4 theory at level k
is (R^8 \times R^8)/D_{2k}, where D_{2k} is the dihedral group of order 4k. We
conjecture that the theory describes two M2-branes on a Z_{2k} ``M-fold'', in
which a geometrical action of Z_{2k} is combined with an action on the branes.
For k=1, this arises as the strong coupling limit of two D2-branes on an O2^-
orientifold, whose worldvolume theory is the maximally supersymmetric SO(4)
gauge theory. Finally, in an appropriate large-k limit we show that one
recovers compactified M-theory and the M2-branes reduce to D2-branes.Comment: 16 pages, LaTeX, v2: typos corrected, included appendices on
Chern-Simons level quantization and monopole charge quantizatio
Super-Yang-Mills and M5-branes
We uplift 5-dimensional super-Yang-Mills theory to a 6-dimensional gauge
theory with the help of a space-like constant vector , whose norm
determines the Yang-Mills coupling constant. After the localization of
the 6D gauge theory acquires Lorentzian invariance as well as scale invariance.
We discuss KK states, instantons and the flux quantization. The 6D theory
admits extended solutions like 1/2 BPS `strings' and monopoles.Comment: 15 pages; minor changes, to appear in JHE
New and old N=8 superconformal field theories in three dimensions
We show that an infinite family of N=6 d=3 superconformal Chern-Simons-matter
theories has hidden N=8 superconformal symmetry and hidden parity on the
quantum level. This family of theories is different from the one found by
Aharony, Bergman, Jafferis and Maldacena, as well as from the theories
constructed by Bagger and Lambert, and Gustavsson. We also test several
conjectural dualities between BLG theories and ABJ theories by comparing
superconformal indices of these theories.Comment: 16 pages, late
Index computation for 3d Chern-Simons matter theory: test of Seiberg-like duality
We work out the superconformal index for N=2 supersymmetric Chern-Simons
matter theories exhibiting Seiberg-like dualities proposed by Giveon and
Kutasov. We consider gauge theories of QCD type and find the
perfect agreements for proposed dual pairs.Comment: References adde
Relating U(N)xU(N) to SU(N)xSU(N) Chern-Simons Membrane theories
By integrating out the U(1)_B gauge field, we show that the U(n)xU(n) ABJM
theory at level k is equivalent to a Z_k identification of the
(SU(n)xSU(n))/Z_n Chern-Simons theory, but only when n and k are coprime. As a
consequence, the k=1 ABJM model for two M2-branes in R^8 can be identified with
the N=8 (SU(2)xSU(2))/Z_2 theory. We also conjecture that the U(2)xU(2) ABJM
model at k=2 is equivalent to the N=8 SU(2)xSU(2)-theory.Comment: 16 pages, Latex; v2: references added; v3: Clarifications adde
On Effective Action of Multiple M5-branes and ABJM Action
We calculate the fluctuations from the classical multiple M5-brane solution
of ABJM action which we found in the previous paper. We obtain D4-brane-like
action but the gauge coupling constant depends on the spacetime coordinate.
This is consistent with the expected properties of M5-brane action, although we
will need to take into account the monopole operators in order to fully
understand M5-branes. We also see that the Nambu-Poisson bracket is hidden in
the solution.Comment: 21 pages; v2:version to appear in JHE
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