118583412
Einstein-Yang-Mills scattering amplitudes from scattering equations
A bstractWe present the building blocks that can be combined to produce tree-level S-matrix elements of a variety of theories with various spins mixed in arbitrary dimensions. The new formulas for the scattering of n massless particles are given by integrals over the positions of n points on a sphere restricted to satisfy the scattering equations. As applications, we obtain all single-trace amplitudes in Einstein-Yang-Mills (EYM) theory, and generalizations to include scalars. Also in EYM but extended by a B-field and a dilaton, we present all double-trace gluon amplitudes. The building blocks are made of Pfaffians and Parke-Taylor-like factors of subsets of particle labels.
15148390
Study of Hadron Scattering Using an Asymmetric Box
jbzhang@zimp.zju.edu.cnWe propose to study hadron-hadron scattering using lattice QCD in an asymmetric box whichallows one to access more non-degenerate low-momentum modes for a given volume. The con-ventional Luscher’s formula applicable in a symmetric box is modiﬁed accordingly. To illustratethe feasibility of this approach, pion-pion elastic scattering phase shifts in the
13895100
C, P, and T of braid excitations in quantum gravity
Abstract We study the discrete transformations of four-valent braid excitations of framed spin networks embedded in a topological three-manifold. We show that four-valent braids allow seven and only seven discrete transformations. These transformations can be uniquely mapped to C, P, T, and their products. Each CPT multiplet of actively-interacting braids is found to be uniquely characterized by a non-negative integer. Finally, braid interactions turn out to be invariant under C, P, and T.
517518
New relations for three-dimensional supersymmetric scattering amplitudes.
We provide evidence for a duality between color and kinematics in three-dimensional supersymmetric Chern-Simons matter theories. We show that the six-point amplitude in the maximally supersymmetric N=8 theory can be arranged so that the kinematic factors satisfy the fundamental identity of three-algebras. We further show that the four- and six-point N=8 amplitudes can be squared into the amplitudes of N=16 three-dimensional supergravity, thus providing evidence for a hidden three-algebra structure in the dynamics of the supergravity.
118969895
The Kinematics of particles moving in rainbow spacetime
The kinematics of massive particles moving in rainbow spacetime is studied. We derive the equation of geodesics when the semiclassical effect of moving particles on the background is taken into account. In particular we show that in rainbow flat spacetime the trajectory of a freely falling particle remains unchanged which is still a straight line in energy-independent coordinate system. The implication to the Unruh effect in rainbow flat spacetime is also discussed.
16635057
The covariant entropy conjecture and concordance cosmological models
Recently a covariant entropy conjecture has been proposed for dynamical horizons. We apply this conjecture to concordance cosmological models, namely, those cosmological models filled with perfect fluids, in the presence of a positive cosmological constant. As a result, we find that this conjecture has a severe constraint power. Not only does this conjecture rule out those cosmological models disfavored by the anthropic principle, but also it imposes an upper bound 10?60 on the cosmological constant for our own universe, which thus provides an alternative macroscopic perspective for understanding the long-standing cosmological constant problem.
53398769
Notes on entanglement entropy in string theory
A bstractIn this paper, we study the conical entropy in string theory in the simplest setup of dividing the nine dimensional space into two halves. This corresponds to the leading quantum correction to the horizon entropy in string theory on the Rindler space. This entropy is also called the conical entropy and includes surface term contributions. We first derive a new simple formula of the conical entropy for any free higher spin fields. Then we apply this formula to computations of conical entropy in open and closed superstring. In our analysis of closed string, we study the twisted conical entropy defined by making use of string theory on Melvin backgrounds. This quantity is easier to calculate owing to the folding trick. Our analysis shows that the conical entropy in closed superstring is UV finite owing to the string scale cutoff.
56229424
Phase structure in a dynamical soft-wall holographic QCD model
A bstractWe consider the Einstein-Maxwell-dilaton system with an arbitrary kinetic gauge function and a dilaton potential. A family of analytic solutions is obtained by the potential reconstruction method. We then study its holographic dual QCD model. The kinetic gauge function can be fixed by requesting the linear Regge spectrum of mesons. We calculate the free energy to obtain the phase diagram of the holographic QCD model and interpret our result as the heavy quarks system by comparing the recent lattice QCD simulation. We finally obtain the equations of state in our model.
121764215
Note on integrability of marginally deformed ABJ(M) theories
A bstractWe study the anomalous dimensions of operators in the scalar sector of β-deformed ABJ(M) theories. We show that the anomalous dimension matrix at two-loop order gives an integrable Hamiltonian acting on an alternating SU(4) spin chain with the spins at odd lattice sides in the fundamental representation and the spins at even lattices in the anti-fundamental representation. We get a set of β-deformed Bethe ansatz equations which give the eigenvalues of Hamiltonian of this deformed spin chain system. Based on our computations, we also extend our study to non-supersymmetric three-parameter γ-deformation of ABJ(M) theories and find that the corresponding Hamiltonian is the same as the one in β-deformed case at two-loop level in the scalar sector.
119288215
Entanglement temperature in non-conformal cases
A bstractPotential reconstruction can be used to find various analytical asymptotical AdS solutions in Einstein dilation system generally. We have generated two simple solutions without physical singularity called zero temperature solutions. We also proposed a numerical way to obtain black hole solution in Einstein dilaton system with special dilaton potential. By using this method, we obtain the corresponding black hole solutions numerically and investigate the thermal stability of the black hole by comparing the free energy of thermal gas and the corresponding black hole. In two groups of non-conformal gravity solutions obtained in this paper, we find that the two thermal gas solutions are more unstable than black hole solutions respectively. Finally, we consider black hole solutions as a thermal state of zero temperature solutions to check that the first thermal dynamical law exists in entanglement system from holographic point of view.
119225430
Logarithmic correction in the deformed AdS{sub 5} model to produce the heavy quark potential and QCD beta function
We study the holographic QCD model, which contains a quadratic term -{sigma}z{sup 2} and a logarithmic term -c{sub 0}log[(z{sub IR}-z)/z{sub IR}] with an explicit infrared cutoff z{sub IR} in the deformed AdS{sub 5} warp factor. We investigate the heavy-quark potential for three cases, i.e., with only a quadratic correction, with both quadratic and logarithmic corrections, and with only a logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation and investigate the corresponding beta function in the Guersoy-Kiritsis-Nitti framework. Our studies show that in the case with only a quadratic correction, a negative {sigma} or the Andreev-Zakharov model is favored to fit the heavy-quark potential and to produce the QCD beta function at 2-loop level; however, the dilaton potential is unbounded in the infrared regime. One interesting observation for the case of positive {sigma} is that the corresponding beta function exists in an infrared fixed point. In the case with only a logarithmic correction, the heavy-quark Cornell potential can be fitted very well, the corresponding beta function agrees with the QCD beta function at 2-loop level reasonably well, and the dilaton potential is bounded from below in the infrared. At the end, we propose a moremore » compact model which has only a logarithmic correction in the deformed warp factor and has less free parameters.« less