Modern Physics Letters A

We present a theory of weak gravity parametrized by a fundamental frequency ${\omega }_0=\sqrt{1-q}H$ of the cosmological horizon, where $H$ and $q$ denote the Hubble and, respectively, deceleration parameter. It predicts (i) a $C^0$ onset to weak gravity across accelerations $\alpha =a_{\mathrm{\text{dS}}}$ in galaxy rotation curves, where $a_{\mathrm{\text{dS}}}=cH$ denotes the de Sitter acceleration with velocity of light $c$, and (ii) fast evolution $Q(z)=dq(z)/dz$ of the deceleration parameter by $\mathrm{\Lambda }={\omega }_0^2$ satisfying $Q_0>2.5$, $Q_0=Q(0)$, distinct from $Q_0\lesssim 1$ in $\mathrm{\Lambda }$CDM. The first is identified in the high resolution data of Lelli et al. (2017), the second in the heterogeneous data on $H(z)$ over $0<z<2$. A model-independent cubic fit in the second rules out $\mathrm{\Lambda }$CDM by $4.35\sigma$ and obtains $H_0=74.0\pm 2.2{\mathrm{\text{km s}}}^{-1}{\mathrm{\text{Mpc}}}^{-1}$ consistent with Riess et al. [Astrophys. J. 826, 56 (2016)]. Comments on possible experimental tests by the LISA Pathfinder are included.

We present a new event mixing cut condition, named energy sum (ES) cut, aiming to investigate two-pion Bose–Einstein correlations (BEC) in reaction with only two identical pions among three final state particles. Unlike the previous proposed pion energy cut, which rejects original events with either pion’s energy beyond a given level, this cut does not eliminate any original events and hence improves the statistics of both original events and mixed events. It selects mixed events in terms of a weight proportional to the two-pion energy sum distribution of original events. Numerical tests using the $\gamma p\to {\pi }^0{\pi }^{0}p$ events are carried out to verify the validity of the energy sum cut. Simulation results show this cut is able to reproduce the relative momentum distribution of the original events in the absence of BEC effects. Its ability to observe BEC effects and to extract correct BEC parameters is verified using event sample in the presence of BEC effects. It is found that the BEC effects can be obviously observed as an enhancement in the correlation function and the BEC parameters extracted by this event mixing cut are in good agreement with input values.

In this paper, we constructed an acoustic thin-shell wormhole (ATW) under neo-Newtonian theory using the Darmois–Israel junction conditions. To determine the stability of the ATW by applying the cut-and-paste method, we found the surface density and surface pressure of the ATW under neo-Newtonian hydrodynamics just after obtaining an analog acoustic neo-Newtonian solution. We focused on the effects of the neo-Newtonian parameters by performing stability analyses using different types of fluids, such as a linear barotropic fluid (LBF), a Chaplygin fluid (CF), a logarithmic fluid (LogF) and a polytropic fluid (PF). We showed that a fluid with negative energy is required at the throat to keep the wormhole stable. The ATW can be stable if suitable values of the neo-Newtonian parameters $\varsigma$, A and B are chosen.

We have extended the analytical transfer matrix (ATM) method to solve quantum mechanical bound state problems with complex PT-symmetric potentials. Our work focuses on a class of models studied by Bender and Jones, we calculate the energy eigenvalues, discuss the critical values of g and compare the results with those obtained from other methods such as exact numerical computation and WKB approximation method.

We have calculated the high spin parton splitting amplitudes postulating the Yangian symmetry of the scattering amplitudes for tensor gluons. The resulting splitting amplitudes coincide with the earlier calculations, which were based on the BCFW recursion relations. The resulting formula unifies all known splitting probabilities found earlier in gauge field theories. It describes splitting probabilities for integer and half-integer spin particles. We also checked that the splitting probabilities fulfil the generalised Kounnas–Ross ${𝒩}$ = 1 supersymmetry relations hinting to the fact that the underlying theory can be formulated in an explicit supersymmetric manner.

We show that the space of observables of test particles has a natural Jacobi structure which is manifestly invariant under the action of the Poincaré group. Poisson algebras may be obtained by imposing further requirements. A generalization of Peierls procedure is used to extend this Jacobi bracket to the space of time-like geodesics on Minkowski spacetime.