119107096
Ferromagnetic neutron stars: axial anomaly, dense neutron matter, and pionic wall
We show that a chiral nonlinear sigma model coupled to degenerate neutrons exhibits a ferromagnetic phase at high density. The magnetization is due to the axial anomaly acting on the parallel layers of neutral pion domain walls spontaneously formed at high density. The emergent magnetic field would reach the QCD scale $\ensuremath{\sim}{10}^{19}\text{ }\text{ }[\mathrm{G}]$, which suggests that the quantum anomaly can be a microscopic origin of the magnetars (highly magnetized neutron stars).
14363850
BIRTH OF CLOSED STRINGS AND DEATH OF OPEN STRINGS DURING TACHYON CONDENSATION
The tremendous progress achieved through the study of black holes and branes suggests that their time-dependent generalizations called Spacelike branes (S-branes) may prove similarly useful. An example of an established approach to S-branes is to include a string boundary interaction and we first summarize evidence for the death of open string degrees of freedom for the homogeneous rolling tachyon on a decaying brane. Then, we review how to extract the flat S-brane worldvolumes describing the homogeneous rolling tachyon and how large deformations correspond to creation of lower dimensional strings and branes. These S-brane worldvolumes are governed by S-brane actions which are on equal footing to D-brane actions, since they are derived by imposing conformality on the string worldsheet, as well as by analyzing fluctuations of time-dependent tachyon configurations. As further examples we generalize previous solutions of the S-brane actions so as to describe multiple decaying and nucleating closed fundamenta...
16844941
ADHM is tachyon condensation
We completely realize the ADHM construction of instantons in D-brane language of tachyon condensations. Every step of the construction is given a physi- cal interpretation in string theory, in a boundary state formalism valid all order in � ' . Accordingly, equivalence between Yang-Mills configurations on D4-branes and D0-branes inside the D4-branes is proven, which shows that small instanton config- urations of the Yang-Mills fields are protected against stringy � ' corrections. We provide also D-brane realizations of the inverse ADHM construction, the complete- ness, and the noncommutative ADHM construction.
53953635
Rapid Thermalization by Baryon Injection in Gauge/Gravity Duality
Using the AdS/CFT correspondence for strongly coupled gauge theories, we calculate thermalization of mesons caused by a time-dependent change of a baryon number chemical potential. On the gravity side, the thermalization corresponds to a horizon formation on the probe flavor brane in the AdS throat. Since heavy ion collisions are locally approximated by a sudden change of the baryon number chemical potential, we discuss implication of our results to RHIC and LHC experiments, to find a rough estimate of rather rapid thermalization time-scale t_{th} < 1 [fm/c]. We also discuss universality of our analysis against varying gauge theories.
14512957
Imaginary Sources: Completeness Conjecture and Charges
While in string theory the subject of sources in imaginary time has received some attention, we demonstrate the power of imaginary sources by proving that they constitute in several field theories a complete basis for all smooth and time dependent source free solutions. These proofs promote the study of imaginary sources to a new and crucial viewpoint for understanding time dependent backgrounds. From our field theory examples we further propose a completeness conjecture that every regular solution to a field equation of motion has a corresponding imaginary source configuration. We define charges for spacelike sources and show their compatibility with the usual charge definition for timelike sources. Many new non-singular time dependent field theory solutions are discussed, including Wick rotations of abelian instantons which demonstrate a close relationship between electric-magnetic duals and analytic continuation.
248467
Branes and BPS Configurations of Non-Commutative/Commutative Gauge Theories
We study BPS Dirac monopole in U(1) gauge theory on non-commutative spacetime. The corresponding brane configuration is obtained in the equivalent ordinary gauge theory through the map proposed by Seiberg and Witten. This configuration coincides exactly with a tilted D-string as predicted. This study provides an interesting check of the equivalence of the non-commutative and ordinary gauge theories.
17561372
The static quark potential in 2+1 flavour Domain Wall QCD from QCDOC
We report our present status of on-going project on the measurement of the static quark potential in 2+1 flavour domain wall QCD with various improved gauge actions and couplings. Lattice spacing determined from Sommer scale on these ensembles are from 1.6 GeV to 2.0 GeV for $16^3 \times 32$ lattice with fifth dimension size 8. We also examine size of discretization error from scaling of a pair of dimensionless quantities, $(r_0 m_\pi)^2$ and $r_0 m_\rho$, and found small scaling violation.