120021706
TUNNELING WITHOUT BARRIERS
Abstract The evolution of quantum fields in theories with relatively flat potentials is considered. It is shown that bubble nucleation, a quantum mechanical tunneling process, may occur even if V ( φ ) has no barrier. Some implications for inflationary universe scenarios are discussed.
7063414
Mass-Deformed Bagger-Lambert Theory and its BPS Objects
We find a 16-supersymmetric mass-deformed Bagger-Lambert theory with SO(4)xSO(4) global R symmetry. The R charge plays the role of the noncentral term in the superalgebra. This theory has one symmetric vacuum and two inequivalent broken sectors of vacua. Each sector of the broken symmetry has SO(4) geometry. We find the 1/2 BPS domain walls connecting the symmetric phase and any broken phase, and 1/4 BPS supertubelike objects, which may appear as anyonic q-balls in the symmetric phase or vortices in the broken phase. We also discuss mass deformations, which reduce the number of supersymmetries.
11205361
The CP(n) model on noncommutative plane
We construct the consistent CP(n) model on noncommutative plane. The Bogomolny bound on the energy is saturated by (anti-)self-dual solitons with integer topological charge, which is independent of their scaling and orientation. This integer quantization is satisfied for our general solutions, which turns out regular everywhere. We discuss the possible implication of our result to the instanton physics in Yang–Mills theories on noncommutative R4.
119250832
New BPS configurations of BMN matrix theory
We explore the 1/2 BPS configurations in BMN matrix theory with SO(3) angular momentum of SO(3) × SO(6) symmetry. The fluctuation analysis of the BPS configurations near the abelian solutions and also the fuzzy two sphere vacua reveals how nonabelian BPS configurations emerge. Especially the irreducible nonabelian configurations seem to have the maximal angular momentum of order N3, beyond which they collapse to abelian ones. We also find some new BPS configurations explicitly.
29030259
Magnetic monopole with Wilson-loop symmetry breaking.
A nonsingular classical magnetic-monopole solution is obtained in a theory with Wilson-loop symmetry breaking. The solution is used to elucidate the quantization rules governing the magnetic charge, which are more restrictive than those for Higgs monopoles.
119199828
The general M5-brane superconformal index
We calculate and study the general superconformal index for the 6d U(N) (2,0) theory with four chemical potentials, from the indices of gauge theories on CP^2 x R. Our index agrees with the large N supergravity index on AdS_7 x S^4 at low energies, and also yields the negative 'Casimir energy' with an N^3 scaling which was recently calculated from a QFT on S^5. Our approach also suggests a systematic study of the (1,0) superconformal indices.
16221979
POLARIZATION EFFECTS ON THE E+E- W+W- PROCESS WITH LARGE EXTRA DIMENSIONS
Abstract We study large extra dimension effects on the polarizations of the W pair and electron beam at the e + e − → W + W − process. It is shown that the measurements of the cross section for transversely polarized W pair with the right-handed electron beam remarkably enhance the possibilities to see the low scale quantum gravity effects. Higher Linear Collider bounds on the string scale in this model can be obtained by using the left-handed electron beam.
118645218
Incorporation of fermions into double field theory
A bstractBased on the stringy differential geometry we proposed earlier, we incorporate fermions such as gravitino and dilatino into double field theory in a manifestly covariant manner with regard to O(D, D) T-duality, diffeomorphism, one-form gauge symmetry for B-field and a pair of local Lorentz symmetries. We note that there are two kinds of fermions in double field theory: O(D, D) singlet and non-singlet which may be identified, respectively as the common and the non-common fermionic sectors in type IIA and IIB suergravities. For each kind, we construct corresponding covariant Dirac operators. Further, we derive a simple criterion for an O(D, D) rotation to flip the chirality of the O(D, D) non-singlet chiral fermions, which implies the exchange of type IIA and IIB supergravities.
16963420
Evolution equation for the heavy quark distribution function in the parton model approach
We explore the perturbative QCD corrections to the inclusive semileptonic decays of $B$ mesons. In inclusive $B$ decay processes the parton picture works well and the scaling feature manifests because the mass of $b$ quark is larger than the QCD scale. Due to this property, the decay rate may be expressed by a single structure function describing the light-cone distribution of $b$ quark apart from the kinematic factor. We derive a $q^2$ evolution equation for the distribution function, which violates the scaling property through the Altarelli-Parisi type approach. The evolution equation is numerically solved and its phenomenological implications are also discussed.
119242266
Stringy unification of type IIA and IIB supergravities under N=2 D=10 supersymmetric double field theory
Abstract To the full order in fermions, we construct D = 10 type II supersymmetric double field theory. We spell the precise N = 2 supersymmetry transformation rules as for 32 supercharges. The constructed action unifies type IIA and IIB supergravities in a manifestly covariant manner with respect to O ( 10 , 10 ) T-duality and a pair of local Lorentz groups, or Spin ( 1 , 9 ) × Spin ( 9 , 1 ) , besides the usual general covariance of supergravities or the generalized diffeomorphism. While the theory is unique, the solutions are twofold. Type IIA and IIB supergravities are identified as two different types of solutions rather than two different theories.
115811530
Vortices and 3 dimensional dualities
We study a supersymmetric partition function of topological vortices in 3d N=4,3 gauge theories on R^2 x S^1, and use it to explore Seiberg-like dualities with Fayet-Iliopoulos deformations. We provide a detailed support of these dualities and also clarify the roles of vortices. The N=4 partition function confirms the proposed Seiberg duality and suggests nontrivial extensions, presumably at novel IR fixed points with enhanced symmetries. The N=3 theories with nonzero Chern-Simons term also have non-topological vortices in the partially broken phases, which are essential for the Seiberg duality invariance of the spectrum. We use our partition function to confirm some properties of non-topological vortices via Seiberg duality in a simple case.