Strong Cosmic Censorship in Charged de Sitter spacetime with Scalar Field Non-minimally Coupled to Curvature

We examine the stability and the strong cosmic censorship in the Reissner-Nordstrom-de Sitter (RN-dS) black hole by investigating the evolution of a scalar field non-minimally coupled to the curvature. We find that when the coupling parameter is negative, the RN-dS black hole experiences instability. The instability disappears when the coupling parameter becomes non-negative. With the increase of the coupling parameter, the violation of the strong cosmic censorship occurs at a larger critical charge ratio. But such an increase of the critical charge is suppressed by the increase of the cosmological constant. Different from the minimal coupling situation, it is possible to accommodate $\beta\ge1$ in the near extremal black hole when the scalar field is non-minimally coupled to curvature. The increase of the cosmological constant can allow $\beta\ge1$ to be satisfied for even smaller value of the coupling parameter. The existence of $\beta\ge1$ implies that the resulting curvature can continuously cross the Cauchy horizon.Comment: 14 pages, 4 figures, 5 table

Bis{2-meth­oxy-6-[(4-methyl­phen­yl)iminiometh­yl]phenolato-κ2 O 1,O 2}tris­(nitrato-κ2 O,O′)methano­lsamarium(III)

The asymmetric unit of the title compound, [Sm(NO3)3(C15H15NO2)2(CH3OH)], contains two Schiff base 2-meth­oxy-6-[(4-methyl­phen­yl)iminiometh­yl]phenolate (HL) ligands, three nitrate ions and one methanol mol­ecule that binds to the nine-coordinate samarium(III) ion via its O atoms. The HL ligands chelate with a strong Sm—O(deprotonated phenolic) bond and a weak Sm—O(meth­oxy) contact. The latter can be inter­preted as the apices of the bicapped square-anti­prismatic SmIIIO9 polyhedron. The Schiff base ligands are in a zwitterionic state with the phenolic H atom transferred to the imine N atom. O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds lend stability to the structure. One O atom of one nitrate group is equally disordered over two positions

Building quantum neural networks based on swap test

Artificial neural network, consisting of many neurons in different layers, is an important method to simulate humain brain. Usually, one neuron has two operations: one is linear, the other is nonlinear. The linear operation is inner product and the nonlinear operation is represented by an activation function. In this work, we introduce a kind of quantum neuron whose inputs and outputs are quantum states. The inner product and activation operator of the quantum neurons can be realized by quantum circuits. Based on the quantum neuron, we propose a model of quantum neural network in which the weights between neurons are all quantum states. We also construct a quantum circuit to realize this quantum neural network model. A learning algorithm is proposed meanwhile. We show the validity of learning algorithm theoretically and demonstrate the potential of the quantum neural network numerically.Comment: 10 pages, 13 figure

Reevaluation of the density dependence of nucleon radius and mass in the global color symmetry model of QCD

With the global color symmetry model (GCM) at finite chemical potential, the density dependence of the bag constant, the total energy and the radius of a nucleon in nuclear matter is investigated. A relation between the nuclear matter density and the chemical potential with the action of QCD being taken into account is obtained. A maximal nuclear matter density for the existence of the bag with three quarks confined within is given. The calculated results indicate that, before the maximal density is reached, the bag constant and the total energy of a nucleon decrease, and the radius of a nucleon increases slowly, with the increasing of the nuclear matter density. As the maximal nuclear matter density is reached, the mass of the nucleon vanishes and the radius becomes infinite suddenly. It manifests that a phase transition from nucleons to quarks takes place.Comment: 18 pages, 3 figure

Bis{[6-meth­oxy-2-(4-methyl­phen­yl)iminiometh­yl]phenolate-κ2 O,O′}tris­(nitrato-κ2 O,O′)europium(III)

The crystal structure of title compound, [Eu(NO3)3(C15H15NO2)2], contains two Schiff base 6-meth­oxy-2-[(4-methyl­phen­yl)imino­meth­yl]phenolate (L) ligands and three independent nitrate ions that chelate to the europium(III) ion via the O atoms. The coordination number of the EuIII ion is ten. The L ligands chelate with a strong Eu—O(deprotonated phenolate) bond and a weak Eu—O(meth­oxy) contact, the latter can be inter­preted as the apices of the bicapped square-anti­prismatic EuIII polyhedron. Intra­molecular N—H⋯O hydrogen bonds occur

Security proof of differential phase shift quantum key distribution in the noiseless case

Differential phase shift quantum key distribution systems have a high potential for achieving high speed key generation. However, its unconditional security proof is still missing, even though it has been proposed for many years. Here, we prove its security against collective attacks with a weak coherent light source in the noiseless case (i.e. no bit error). The only assumptions are that quantum theory is correct, the devices are perfect and trusted and the key size is infinite. Our proof works on threshold detectors. We compute the lower bound of the secret key generation rate using the information-theoretical security proof method. Our final result shows that the lower bound of the secret key generation rate per pulse is linearly proportional to the channel transmission probability if Bob's detection counts obey the binomial distribution.Comment: Published version, 13 pages, 4 figures, minor changes, references added, acknowledgement adde