119464468
Two Particle States in a Box and the $s$-Matrix in Multi-Channel Scattering
Using a quantum mechanical model, the exact energy eigenstates for two-particle two-channel scattering are studied in a cubic box with periodic boundary conditions. 
A relation between the exact energy eigenvalue in the box and the two-channel $S$-matrix elements in the continuum is obtained. This result can be viewed as a generalization of the well-known L\"uscher's formula which establishes a similar relation in elastic scattering.
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
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.
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.
118716317
Note on entanglement temperature for low thermal excited states in higher derivative gravity
A bstractWe investigate the entanglement temperature of a small scale subsystem in low excited states by using holographic method. Especially, we study the entanglement entropy and entanglement temperature in higher derivative gravities which are considered as low thermal excitation of pure AdS gravity. We find that the entanglement entropy are related to the central charges of CFT living on the boundary. The relation between the variance of entanglement entropy and energy of a small scale subsystem has been also obtained. Furthermore, the relation is consistent with the first law-like relation that is proposed by Phys. Rev. Lett. 110 (2013)091602. Finally, we derive the formula of the variance of entanglement entropy in general excited states in gravity background with the Fefferman-Graham coordinates and the entanglement temperature can be figured out in special case.
118493750
Massive superstring scatterings in the Regge regime
We calculate four classes of high-energy massive string scattering amplitudes of fermionic string theory at arbitrary mass levels in the Regge regime (RR). We show that all four leading order amplitudes in the RR can be expressed in terms of the Kummer function of the second kind. Based on the summation algorithm of a set of extended signed Stirling number identities, we show that all four ratios calculated previously by the method of decoupling of zero-norm states among scattering amplitudes in the Gross regime can be extracted from this Kummer function in the RR. Finally, we conjecture and give evidence that the existence of these four Gross regime ratios in the RR persists to subleading orders in the Regge expansion of all high-energy fermionic string scattering amplitudes.
32091410
Rényi entropy of locally excited states with thermal and boundary effect in 2D CFTs
A bstractWe study Rényi entropy of locally excited states with considering the thermal and boundary effects respectively in two dimensional conformal field theories (CFTs). Firstly, we consider locally excited states obtained by acting primary operators on a thermal state in low temperature limit. The Rényi entropy is summation of contribution from thermal effect and local excitation. Secondly, we mainly study the Rényi entropy of locally excited states in 2D CFT with a boundary. We show that the time evolution of Rényi entropy is affected by the boundary, but does not depend on the boundary condition. Moreover, we show that the maximal value of Rényi entropy always coincides with the log of quantum dimension of the primary operator. In terms of quasi-particle interpretation, the boundary behaves as an infinite potential barrier which reflects any energy moving towards it.
118364646
Scalar Mesons and glueballs in $Dp-Dq$ hard-wall models
Chao Wang, Song He, Mei Huang, Qi-Shu Yan, and Yi Yang 1 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China 2 Theoretical Physics Center for Science Facilities, Chinese Academy of Sciences, Beijing, China 3 Department of Physics, University of Toronto, Toronto, Canada 4 Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan and 5 Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan (Dated: February 5, 2009)
76649422
A hQCD model and its phase diagram in Einstein-Maxwell-Dilaton system
A bstractBy use of the potential reconstruction approach we obtain a series of asymptotically AdS (aAdS) black hole solutions in an Einstein-Maxwell-Dilaton (EMD) system. Basing on the solutions of the system, we reconstruct a semi-analytical holographic QCD (hQCD) model with a quadratic term in warped factor. We discuss some aspects of the hQCD model, in particular we calculate the free energy of two static color sources (a heavy quark-antiquark pair) which is an important order parameter to describe confinement/deconfinement phase transition. The behavior of the free energy with respect to temperature and chemical potential is studied. We find that in the hQCD model the deconfinement phase transition can be realized and a critical point occurs. The resulting phase diagram in the temperature-chemical potential T − μ plane is in quite good agreement with the one from recent lattice results and effective models of QCD.