1,958 research outputs found

    Estimating the Stochastic Sickness Effect on Employment, Worktime and Saving Decisions

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    This paper aims to study labor supply and saving decisions as a result of health uncertainty. O’Donnell (1995) suggested a theoretical positive relationship between working hours (or saving rate) and the perceived health uncertainty. That is, for risk-averse individuals, there exists a precaution motion to work harder and save more when facing the uncertainty for the health condition. We test this hypothetical relationship by applying the 2003-2005 data from the Panel Study of Family Dynamics (PSFD) in Taiwan. Following Hughes and Maguire’s approach (2003), our estimation result indicates that a stochastic sickness has positive effects on the decisions of working time and saving rate.Health, Uncertainty, Labor Supply, Saving

    Quench Dynamics of Topological Maximally-Entangled States

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    We investigate the quench dynamics of the one-particle entanglement spectra (OPES) for systems with topologically nontrivial phases. By using dimerized chains as an example, it is demonstrated that the evolution of OPES for the quenched bi-partite systems is governed by an effective Hamiltonian which is characterized by a pseudo spin in a time-dependent pseudo magnetic field S(k,t)\vec{S}(k,t). The existence and evolution of the topological maximally-entangled edge states are determined by the winding number of S(k,t)\vec{S}(k,t) in the kk-space. In particular, the maximally-entangled edge states survive only if nontrivial Berry phases are induced by the winding of S(k,t)\vec{S}(k,t). In the infinite time limit the equilibrium OPES can be determined by an effective time-independent pseudo magnetic field \vec{S}_{\mb{eff}}(k). Furthermore, when maximally-entangled edge states are unstable, they are destroyed by quasiparticles within a characteristic timescale in proportional to the system size.Comment: 5 pages, 3 figure

    Edge State, Entanglement Entropy Spectra and Critical Hopping Coupling of Anisotropic Honeycomb Lattice

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    For a bipartite honeycomb lattice, we show that the Berry phase depends not only on the shape of the system but also on the hopping couplings. Using the entanglement entropy spectra obtained by diagonalizing the block Green's function matrices, the maximal entangled state with the eigenvalue λm=1/2\lambda_m=1/2 of the reduced density matrix is shown to have one-to-one correspondence to the zero energy states of the lattice with open boundaries, which depends on the Berry phase. For the systems with finite bearded edges along xx-direction we find critical hopping couplings: the maximal entangled states (zero-energy states) appear pair by pair if one increases the hopping coupling hh over the critical couplings hch_cs.Comment: 4 pages, 4 figure

    Dimerized and trimerized phases for spin-2 Bosons in a one-dimensional optical lattice

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    We study the phase diagram for spin-2 bosons loaded in a one-dimensional optical lattice. By using non-Abelian density matrix renormalization group (DMRG) method we identify three possible phases: ferromagnetic, dimerized, and trimerized phases. We sketch the phase boundaries based on DMRG. We illustrate two methods for identifying the phases. The first method is based on the spin-spin correlation function while in the second method one observes the excitation gap as a dimerization or a trimerization superlattice is imposed. The advantage of the second method is that it can also be easily implemented in experiments. By using the scattering lengths in the literature we estimate that 83^{83}Rb, 23^{23}Na, and 87^{87}Rb be ferromagnetic, dimerized, and trimerized respectively.Comment: 4 pages, 3 figures. Add acknowledgemen

    On Holographic Dual of the Dyonic Reissner-Nordstr\"om Black Hole

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    It is shown that the hidden conformal symmetry, namely SO(2,2)SL(2,R)L×SL(2,R)RSO(2,2) \sim SL(2,R)_L \times SL(2,R)_R symmetry, of the non-extremal dyonic Reissner-Nordstr\"om black hole can be probed by a charged massless scalar field at low frequencies. The existence of such hidden conformal symmetry suggests that the field theory holographically dual to the 4D Reissner-Nordstr\"om black hole indeed should be a 2D CFT. Although the associated AdS3_3 structure does not explicitly appear in the near horizon geometry, the primary parameters of the dual CFT2_2 can be exactly obtained without the necessity of embedding the 4D Reissner-Nordstr\"om black hole into 5D spacetime. The duality is further supported by comparing the absorption cross sections and real-time correlators obtained from both the CFT and the gravity sides.Comment: 18 pages, no figure, typos correcte

    Twofold Hidden Conformal Symmetries of the Kerr-Newman Black Hole

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    In this paper, we suggest that there are two different individual 2D CFTs holographically dual to the Kerr-Newman black hole, coming from the corresponding two possible limits --- the Kerr/CFT and Reissner-Nordstr\"om/CFT correspondences, namely there exist the Kerr-Newman/CFTs dualities. A probe scalar field at low frequencies turns out can exhibit two different 2D conformal symmetries (named by JJ- and QQ-pictures, respectively) in its equation of motion when the associated parameters are suitably specified. These twofold dualities are supported by the matchings of entropies, absorption cross sections and real time correlators computed from both the gravity and the CFT sides. Our results lead to a fascinating "microscopic no hair conjecture" --- for each macroscopic hair parameter, in additional to the mass of a black hole in the Einstein-Maxwell theory, there should exist an associated holographic CFT2_2 description.Comment: 21 pages, 1 figure, typos correcte

    Quantum Critical Spin-2 Chain with Emergent SU(3) Symmetry

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    We study the quantum critical phase of a SU(2) symmetric spin-2 chain obtained from spin-2 bosons in a one-dimensional lattice. We obtain the scaling of the entanglement entropy and finite-size energies by exact diagonalization and density-matrix renormalization group methods. From the numerical results of the energy spectrum, central charge, and scaling dimension we identify the conformal field theory describing the whole critical phase to be the SU(3)1_1 Wess-Zumino-Witten model. We find that while in the whole critical phase the Hamiltonian is only SU(2) invariant, there is an emergent SU(3) symmetry in the thermodynamic limit
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