26,698 research outputs found
4d =2 theories with disconnected gauge groups
In this paper we present a beautifully consistent web of evidence for the
existence of interacting 4d rank-1 SCFTs obtained from gauging
discrete subgroups of global symmetries of other existing 4d rank-1
SCFTs. The global symmetries that can be gauged involve a
non-trivial combination of discrete subgroups of the , low-energy EM
duality group , and the outer automorphism group of the
flavor symmetry algebra, Out().
The theories that we construct are remarkable in many ways: (i) two of them
have exceptional and flavor groups; (ii) they substantially
complete the picture of the landscape of rank-1 SCFTs as they
realize all but one of the remaining consistent rank-1 Seiberg-Witten
geometries that we previously constructed but were not associated to known
SCFTs; and (iii) some of them have enlarged SUSY, and have not
been previously constructed. They are also examples of SCFTs which violate the
Shapere-Tachikawa relation between the conformal central charges and the
scaling dimension of the Coulomb branch vev. We propose a modification of the
formulas computing these central charges from the topologically twisted Coulomb
branch partition function which correctly compute them for discretely gauged
theories.Comment: 45 pages, 3 figure
Coulomb branches with complex singularities
We construct 4d superconformal field theories (SCFTs) whose Coulomb branches
have singular complex structures. This implies, in particular, that their
Coulomb branch coordinate rings are not freely generated. Our construction also
gives examples of distinct SCFTs which have identical moduli space (Coulomb,
Higgs, and mixed branch) geometries. These SCFTs thus provide an interesting
arena in which to test the relationship between moduli space geometries and
conformal field theory data.
We construct these SCFTs by gauging certain discrete global symmetries of
superYang-Mills (sYM) theories. In the simplest cases, these
discrete symmetries are outer automorphisms of the sYM gauge group, and so
these theories have lagrangian descriptions as sYM theories with
disconnected gauge groups.Comment: 43 page
A spaceship with a thruster - one body, one force
A spaceship with one thruster producing a constant magnitude force is
analyzed for various initial conditions. This elementary problem, with one
object acted upon by one force, has value as a challenge to one's physical
intuition and in demonstrating the benefits and limitations of dimensional
analysis. In addition, the problem can serve to introduce a student to special
functions, provide a mechanical model for Fresnel integrals and the associated
Cornu spiral, or be used as an example in a numerical methods course. The
problem has some interesting and perhaps unexpected features.Comment: 8 pages, 12 figures. Submitted to the American Journal of Physics.
After it is published, it will be found at http://scitation.aip.org/aj
Medical diagnostics using designed molecules with sense and logic
Luminescent molecules responsive to cations, anions and even small molecules can be designed with the appropriate selectivity and sensitivity for monitoring physiological and pathological levels of analytes. We highlight some recent examples of designed molecules that can sense for a specific analyte or a combination of analytes in blood and in living cells. Furthermore, we demonstrate how molecules can be designed with built-in algorithms according to principles of Boolean logic to perform information processing. The potential future application of molecular systems able to perform multi-analyte sensing as `lab-on-a-molecule' systems for medical and environmental diagnostics is also presented.peer-reviewe
The thermal statistics of quasi-probabilities' analogs in phase space
We focus attention upon the thermal statistics of the classical analogs of
quasi-probabilities's (QP) in phase space for the important case of quadratic
Hamiltonians. We consider the three more important OPs: 1) Wigner's, -, and
Husimi's. We show that, for all of them, the ensuing semiclassical entropy is a
function {\it only} of the fluctuation product . We
ascertain that {\it the semi-classical analog of the -distribution} seems to
become un-physical at very low temperatures. The behavior of several other
information quantifiers reconfirms such an assertion in manifold ways. We also
examine the behavior of the statistical complexity and of thermal quantities
like the specific heat.Comment: 11 pages, 6 figures.Text has change
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