Modern Physics Letters A

The long baseline neutrino experiments, T2K and NO$\nu$A, have taken significant amount of data in each of the four channels: (a) ${\nu }_{\mu }$ disappearance, (b) ${\bar{\nu }}_{\mu }$ disappearance, (c) ${\nu }_e$ appearance, and (d) ${\bar{\nu }}_e$ appearance. There is a mild tension between the disappearance and the appearance data sets of T2K. A more serious tension exists between the ${\nu }_e$ appearance data of T2K and the ${\nu }_e/{\bar{\nu }}_e$ appearance data of NO$\nu$A. This tension is significant enough that T2K rules out the best-fit point of NO$\nu$A at 95% confidence level, whereas, NO$\nu$A rules out T2K best-fit point at 90% confidence level. We explain the reason why these tensions arise. We also do a combined fit of T2K and NO$\nu$A data and comment on the results of this fit.

The modified gravity is considered in the framework of the holographic dark energy (DE). An analysis of the autonomous system, the critical points and their stability is presented. Unlike the DE models based on $f(R)$, it is found that working in the holographic frame enriches the possibility of accelerated and matter-type points for different cosmological scenarios, making viable trajectories of successful $f(R)$ models that are not allowed without the consideration of the holographic framework. The implications for the Hu–Sawicki model are analyzed.

By the use of coherent and squeezed thermal states formalism, we analyzed the phenomena of particle creation when coherently oscillating a homogeneous scalar field (Inflaton) in semi-classical gravity. We also obtained an estimated solution for the semi-classical Einstein equation in non-classical thermal states formalism perturbatively, which is similar to the power-law expansion of classical Einstein equation. This solution, apart from a particular condition, shows oscillatory behavior in nature. We also analyzed a coherently oscillating homogeneous scalar field, in a thermal vacuum, coherent thermal, squeezed thermal vacuum and coherent squeezed thermal states, suffering from particle creation, and created particles are showing oscillatory behavior. Particle production can be raised due to thermal and quantum effects. We also studied quantum fluctuations of a homogeneous scalar field in the above-mentioned non-classical thermal states.

In this paper, we have investigated the Meissner effect of holographic superconductors in the presence of Dirac–Born–Infeld electrodynamics. The matching method is applied to obtain the critical magnetic field and the critical temperature. The critical magnetic field obtained from this investigation shows the effects of the DBI parameter $b$ and differs from that obtained from Born electrodynamics because of the extra $\overrightarrow{E}\cdot \overrightarrow{B}$ term in the Dirac–Born–Infeld theory. It is observed that the critical magnetic field increases in Dirac–Born–Infeld theory compared to that in the Born theory.

In this paper, we have studied Noether symmetries of locally rotationally symmetric (LRS) Bianchi type V spacetimes. Solving the determining equations of Noether symmetries, it is concluded that the dimension of Noether algebra for these spacetimes is 5, 6, 7, 9, 10, 11 or 17. For all Noether symmetry generators, we have presented the corresponding conservation laws and the Lie algebra. Moreover, some physical implications of the obtained metrics are discussed, which include the study of different energy conditions.

This paper deals with the symmetry analysis of the Einstein Cartan Theory [E. Cartan, C. R. Acad. Sci. (Paris) 174, 593 (1922); E. Cartan, Ann. Sci. Ec. Norm. Super 40, 325 (1923)] which is an extension of the general relativity and it accounts for the spacetime torsion [S. Basilakos et al., Phys. Rev. D 88, 103526 (2013)]. We begin by applying Noether theorem [S. Capozziello, La Rivista del Nuovo Cimento (1978–1999) 19(4), 1 (1996)] to the Lagrangian of the FRW type cosmology with torsion and choose a point transformation: $(a,\varphi ,N)\to (u,v,W)$, such that one of the transformed variables is cyclic [S. Capozziello, M. De Laurentis and S. D. Odintsov, Eur. Phys. J. C 72, 2068 (2012)] for the Lagrangian. Then using the conserved charge [S. Capozziello, M. De Laurentis and S. D. Odintsov, Eur. Phys. J. C 72, 2068 (2012)], which is obtained by applying Noether theorem, and the constant of motion, we get the solutions and conclude that due to the presence of torsion, the FRW type cosmology is in the de Sitter phase [D. Kranas, C. G. Tsagas, J. D. Barrow and D. Iosifidis, Eur. Phys. J. C 79, 341 (2019)].

ISIM(2) symmetry group of Cohen and Glashow’s very special relativity is unstable with respect to small deformations of its underlying algebraic structure, and according to Segal’s principle cannot be a true symmetry of nature. However, like special relativity, which is a very good description of nature, thanks to the smallness of the cosmological constant, which characterizes the deformation of the Poincaré group, the very special relativity can also be a very good approximation, thanks to the smallness of the dimensionless parameter characterizing the deformation of ISIM(2).

In this work, we investigate wormhole configurations described by a constant redshift function in Einstein-Cubic gravity (ECG). We derive analytical wormhole geometries by assuming a particular equation of state (EoS) and investigate the possibility that these solutions satisfy the standard energy conditions. We introduce exact asymptotically flat and anti-de Sitter (AdS) spacetimes that admit traversable wormholes. These solutions are obtained by imposing suitable values for the parameters of the theory so that the resulted geometries satisfy the weak energy condition (WEC) in the vicinity of the throat, due to the presence of higher-order curvature terms. Moreover, we find that AdS solutions satisfy the WEC throughout the spacetime. A description of the geodesic motion of time-like and null particles is presented for the obtained wormhole solutions. Also, using gravitational lensing effects, observational features of the wormhole structure are discussed.

We present a supersymmetric generalization of integrable AB system and its associated Lax pair in superspace. We obtain component field equations of super integrable AB system. We also relate super integrable AB system to super sine-Gordon equation in superspace as well as at the component level.

In this paper, using Kempf and Mangano’s generalized uncertainty principle (GUP) [A. Kempf and G. Mangano, Phys. Rev. D 55, 7909 (1997)], we introduce a GUP which is called GUP*. The minimum measurable length predicted by the GUP* leads to the existence of a maximum momentum, in agreement with various previous studies. Then, we investigate some deformed calculus including both exponential and differential cases. Finally, as some applications of this GUP*, we discuss some quantum mechanical problems and obtain the results.

In 2017, Qin and Dai [Quantum Inf. Process. 16, 64 (2017). https://doi.org/10.1007/s11128-017-1525-y], proposed a dynamic quantum secret sharing (DQSS) scheme based on the d-dimensional state. However, as shown in this study, a malicious participant can reveal the secret key of other participants without being detected. Furthermore, this study identifies a security issue in Qin and Dai’s DQSS protocol pertaining to the honesty of a revoked participant. Without considering these security issues, the DQSS protocol could fail at providing secret-sharing function. Therefore, two improvements are proposed to circumvent these problems.

We have formulated a semi-empirical formula for alpha decay half-lives and cluster decay half-lives for superheavy nuclei of atomic number range $104\le Z\le 130$. We have compared the logarithmic half-lives produced by the present formula with that of experiments and other formulae, such as universal decay law (UDL) [H. C. Manjunatha and K. N. Sridhar, Eur. Phys. J. A 53, 156 (2017)] and Horoi et al. [Horoi et al., J. Phys. G$:$ Nucl. Part. Phys. 30, 945 (2004)], Univ [D. Ni and Z. Ren, Phys. Rev. C 74, 014304 (2006)], Royer [G. Royer, J. Phys. G: Nucl. Part. Phys. 26, 1149 (2000)] and VSS [S. A. Gurvitz and G. Kalbermann, Phys. Rev. Lett. 59, 262 (1987)]. The constructed formula produces logarithmic half-lives for alpha and cluster decay (⁴He,⁹Be, ${}^{10,11}$B, ${}^{12}$C, ${}^{14}$N, ${}^{16}$O, ${}^{19}$F, ${}^{20-22}$Ne, ${}^{23}$Na, ${}^{24-26}$Mg, ${}^{27}$Al, ${}^{28-30}$Si, ${}^{31}$P, ${}^{32-34}$S, ${}^{35}$Cl, ${}^{36,38,40}$Ar, ${}^{39,41}$K and ${}^{40,42-44,46}$Ca) in superheavy nuclei of atomic number range $104\le Z\le 130$.