In the minimal supersymmetric standard model (MSSM), the bino-wino coannihilation provides a feasible way to accommodate the observed cosmological dark matter (DM) relic density. However, such a scenario usually predicts a very small DM-nucleon scattering cross section that is below the neutrino floor, and can not be tested by DM direct detection experiments. In this work, we investigate the discovery potential of this bino-wino co-annihilation region by searching for the soft dilepton events from the process $pp\to {\chi }_2^0(\to {\ell }^{+}{\ell }^{-}{\chi }_1^0){\chi }_1^{\pm }+\text{jets}$ at the LHC. We find that the mass of the winolike ${\chi }_2^0$ can be probed up to about 310 (230) GeV at $2\sigma$ ($5\sigma$) level for an integrated luminosity $\mathcal{L}=300{\mathrm{fb}}^{-1}$. In the future HL-LHC with $3000{\mathrm{fb}}^{-1}$ luminosity, the corresponding mass limits can be pushed up to 430 (330) GeV.

In this work we investigate the impact of intrinsic charm on the prompt atmospheric neutrino flux. The color dipole approach to heavy quark production is generalized to include the contribution of processes initiated by charm quarks. The prompt neutrino flux is calculated assuming the presence of intrinsic charm in the wave function of the projetile hadron. The predictions are compared with previous color dipole results which were obtained taking into account only the process initiated by gluons. In addition, we estimate the atmospheric ($\mathrm{conventional}+\text{prompt}$) neutrino flux and compare our predictions with the ICECUBE results for the astrophysical neutrino flux. Our results demonstrate that the contribution of the charm quark initiated process is non—negligible and that the prompt neutrino flux can be enhanced by a factor $\approx 2$ at large neutrino energies if an intrinsic charm component is present in the proton wave function.

We study the $Y(2175)$ using the method of QCD sum rules. There are two independent $ss\overline{s}\overline{s}$ interpolating currents with $J^{PC}=1^{--}$, and we calculate both their diagonal and their off-diagonal correlation functions. We obtain two new currents that do not strongly correlate to each other, so they may couple to two different physical states: one of them couples to the $Y(2175)$, while the other may couple to another state whose mass is evaluated to be $2.41\pm 0.25\mathrm{GeV}$. Evidence of the latter state can be found in the BABAR [B. Aubert et al. (BABAR Collaboration), Phys. Rev. D 76, 012008 (2007)], BESII [M. Ablikim et al. (BES Collaboration), Phys. Rev. Lett. 100, 102003 (2008)], Belle [C. P. Shen et al. (Belle Collaboration), Phys. Rev. D 80, 031101 (2009)], and BESIII [M. Ablikim et al. (BESIII Collaboration), Phys. Rev. D 91, 052017 (2015)] experiments.

In this paper, we analyze the exclusive vector meson photoproduction in the recent run using xenon ions at energy of 5.44 TeV performed by the Large Hadron Collider. We focus on the ultraperipheral collisions and provide theoretical predictions for coherent and incoherent cross sections within the color dipole approach and gluon saturation framework. The rapidity distribution is investigated in both cases and comparison to other approaches available in the literature is completed. We show that the expected yields are enough to perform reliable cross section measurements for light mesons as ${\rho }^0$ and $\varphi$.

Motivated by the ability to consistently apply the Ryu-Takayanagi prescription for general convex surfaces and the relationship between entanglement and geometry in tensor networks, we introduce a novel, covariant bulk object—the holographic slice. The holographic slice is found by considering the continual removal of short-range information in a boundary state. It thus provides a natural interpretation as the bulk dual of a series of coarse-grained holographic states. The slice possesses many desirable properties that provide consistency checks for its boundary interpretation. These include the monotonicity of both area and entanglement entropy, uniqueness, and the inability to probe beyond late-time black hole horizons. Additionally, the holographic slice illuminates physics behind entanglement shadows, as minimal-area extremal surfaces anchored to a coarse-grained boundary may probe entanglement shadows. This lets the slice flow through shadows. To aid in developing intuition for these slices, many explicit examples of holographic slices are investigated. Finally, the relationship to tensor networks and renormalization (particularly in $\mathrm{AdS}/\mathrm{CFT}$) is discussed.

The Carnot heat engine sets an upper bound on the efficiency of a heat engine. As an ideal, reversible engine, a single cycle must be performed in infinite time, and so the Carnot engine has zero power. However, there is nothing, in principle, forbidding the existence of a heat engine whose efficiency approaches that of Carnot while maintaining finite power. Such an engine must have very special properties, some of which have been discussed in the literature, in various limits. While recent theorems rule out a large class of engines from maintaining finite power at exactly the Carnot efficiency, the approach to the limit still merits close study. Presented here is an exactly solvable model of such an approach that may serve as a laboratory for exploration of the underlying mechanisms. The equations of state have their origins in the extended thermodynamics of electrically charged black holes.

We investigate quantum entanglement between two symmetric spatial regions in de Sitter space with the Bunch-Davies vacuum. As a discretized model of the scalar field for numerical simulation, we consider a harmonic chain model. Using the coarse-grained variables for the scalar field, it is shown that the multipartite entanglement on the superhorizon scale exists by checking the monogamy relation for the negativity which quantifies the entanglement between the two regions. Further, we consider the continuous limit of this model without coarse-graining and find that non-zero values of the logarithmic negativity exist even if the distance between two spatial regions is larger than the Hubble horizon scale.

A natural star product for 4-d $\kappa$-Minkowski space is used to investigate various classes of $\kappa$-Poincaré invariant scalar field theories with quartic interactions whose commutative limit coincides with the usual ${\varphi }^4$ theory. $\kappa$-Poincaré invariance forces the integral involved in the actions to be a twisted trace, thus defining a Kubo-Martin-Schwinger (KMS) weight for the noncommutative (${\mathrm{C}}^{*}$-)algebra modeling the $\kappa$-Minkowski space. In all the field theories, the twist generates different planar one-loop contributions to the 2-point function which are at most UV linearly diverging. Some of these theories are free of UV/IR mixing. In the others, UV/IR mixing shows up in non-planar contributions to the 2-point function at exceptional zero external momenta while staying finite at nonzero external momenta. These results are discussed together with the possibility for the KMS weight relative to the quantum space algebra to trigger the appearance of KMS state on the algebra of observables.

In this work we shall investigate the occurrence of future cosmological finite-time singularities in the dynamical system corresponding to two cosmological theories, namely that of vacuum $f(R)$ gravity and that of three fluids. As we shall make clear, a finite-time cosmological singularity may be entirely different from a finite-time singularity of a dynamical system, since the latter mainly depends on the behavior of the dynamical system variables. The vacuum $f(R)$ gravity is an example for which the variables we will choose to quantify the phase space dynamics, do not necessarily blow up near a cosmological singularity. After appropriately choosing the variables, we shall investigate the behavior of the corresponding dynamical system near some types of cosmological finite-time singularities, for some limiting cases in which we can produce analytic solutions for the dynamical variables. The most interesting case from both a mathematical and physical point of view, is the big rip case, and particularly in the limiting case of a very strong singularity. The physically appealing outcome is that the resulting nonautonomous dynamical system is attracted asymptotically to an accelerating attractor solution, with equation-of-state parameter $w_{\mathrm{eff}}=-1$. Our analytic results, show that an extremely strong big rip singularity in vacuum $f(R)$ gravity theories is always related to an accelerating solution, or tends to acceleration. The converse statement though may not be true. We also perform the same analysis for the Type IV finite-time singularity, and we investigate the behavior of the dynamical system near the Type IV singularity, in the case that the singularity is extremely soft, in which case we are able to produce analytic expressions for the dynamical solutions. Also we briefly discuss how the removal of the finite-time singularity may be achieved by the addition of an $R^2$ term in the $f(R)$ gravity action. The second cosmology we shall study is a multifluid cosmology, consisting of three fluids: the interacting dark matter and dark energy fluids, and the baryonic fluid. By appropriately choosing the variables, we will show that the dynamical system can become an autonomous polynomial dynamical system, in which case, by using a dominant balance analysis, we shall investigate the occurrence of finite-time singularities in this system. We also study numerically and analytically, in some detail, the phase space of the dynamical system for some specific forms of the dark energy–dark matter interaction term.

We investigate thermodynamic phase structure and critical behavior of Born-Infeld (BI) black holes in an anti-de Sitter (AdS) space, where the charge of the system can vary and the cosmological constant (pressure) is fixed. We find that the BI parameter crucially affects the temperature of the black hole when the horizon radius, $r_{+}$, is small. We observe that depending on the value of the nonlinear parameter, $\beta$, BI-AdS black hole may be identified as RN black hole for $Q\ge Q_m$, and Schwarzschild-like black hole for $Q<Q_m$, where $Q_m=1/(8\pi \beta )$ is the marginal charge. We analytically calculate the critical point ($Q_c$, $T_c$, $r_{+c}$) by solving the cubic equation and study the critical behavior of the system. We also explore the behavior of Gibbs free energy for BI-AdS black hole. We find out that the phase behavior of BI-AdS black hole depends on the charge $Q$. For $Q>Q_c$, the Gibbs free energy is single valued and the system is locally stable ($C_Q>0$), while for $Q<Q_c$, it becomes multivalued and $C_Q<0$. In the range of $Q_z<Q<Q_c$, a first order phase transition occurs between small black hole (SBH) and large black hole (LBH). Interestingly enough, in the range of $Q_t\le Q\le Q_z$, a reentrant phase transition occurs between intermediate (large) black hole, SBH and LBH in Schwarzschild-type region. This means that in addition to the first order phase transition which separates SBH and LBH, a finite jump in Gibbs free energy leads to a zeroth order phase transition between SBH and intermediate black hole (LBH) where initiates from $Q=Q_z$ and terminates at $Q=Q_t$.

The minimal theory of massive gravity (MTMG) has two branches of stable cosmological solutions: a self-accelerating branch, which, except for the mass of tensor modes, has exactly the same behavior of linear perturbations as $\mathrm{\Lambda }\mathrm{CDM}$ in general relativity (GR), and a normal branch with nontrivial behavior. We explore the influence of the integrated Sachs-Wolfe-galaxy correlation constraints on the normal branch of MTMG, which, in its simplest implementation, has one free parameter more than $\mathrm{\Lambda }\mathrm{CDM}$ in GR (or the self-accelerating branch of MTMG): $\theta$. This parameter is related to the graviton mass and only affects the behavior of the cosmological linear perturbation dynamics. Using 2d-mass and SDSS data, we check which values of $\theta$ lead to a positive or negative cross-correlation. We find that positive cross-correlation is achieved for a large parameter-space interval. Within this allowed region of parameter space, we perform a ${\chi }^2$ analysis in terms of the parameter $\theta$, while keeping the other background parameters fixed to the best-fit values of Planck. We then infer that the normal branch of MTMG fits the data well in a nontrivial portion of the parameter space, and future experiments should be able to distinguish such a model from $\mathrm{\Lambda }\mathrm{CDM}$ in GR (or the self-accelerating branch of MTMG).

We present the reconstruction method of $f(R)$ gravity for the homogeneous and anisotropic Bianchi-I spacetime, which was previously formulated only for homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker spacetime. We argue in this paper that for anisotropic spacetimes, the total anisotropy behaves as an independent metric degree of freedom (d.o.f.) on top of the average scale factor in $f(R)$ gravity. This is not like general relativity, where specifying the form of the average scale factor as a function of time also specifies the total anisotropy as a function of time uniquely. We link this peculiar fact to an interesting intertwining between the definition of Ricci scalar for anisotropic metric and anisotropy evolution equation in $f(R)$ gravity. Consequently, specifying an anisotropic solution of $f(R)$ gravity implies specifying both the average scale factor and the total anisotropy as functions of time. The reconstruction method hence formulated is applied to two scenarios where anisotropy suppression is important, namely, a quasi-de-Sitter expansion as required in inflation, and a power law contraction as required in ekpyrotic bounce models.

In this paper we study nonextremal isolated horizons embeddable in 4-dimensional spacetimes satisfying the vacuum Einstein equations with cosmological constant. The horizons are assumed to be stationary to the second order. The Weyl tensor at the horizon is assumed to be of the Petrov type D. The corresponding equation on the intrinsic horizon geometry is solved in the axisymmetric case. The family of the solutions is 2-dimensional and it is parametrized by the area and the angular momentum. The embeddability in the Kerr-(anti) de Sitter and the near extremal horizon spacetimes obtained by the Horowitz limit from the extremal Kerr-de Sitter and extremal Kerr–anti-de Sitter is discussed. This uniqueness of the axisymmetric type D isolated horizons is a generalization of an earlier similar result valid in the cosmological constant free case.

A unification of dark matter and dark energy based on a dynamical spacetime theory is suggested. By introducing a dynamical spacetime vector field ${\chi }_{\mu }$ as a Lagrange multiplier, conservation of an energy momentum tensor $T_{(\chi )}^{\mu \nu }$ is implemented. This Lagrangian generalizes the “unified dark energy and dark matter from a scalar field different from quintessence” [Phys. Rev. D 81, 043520 (2010)], which did not consider a Lagrangian formulation. This generalization allows the solutions which were found previously, but in addition to that also nonsingular bouncing solutions that rapidly approach to the $\mathrm{\Lambda }\mathrm{CDM}$ model. The dynamical time vector field exactly coincides with the cosmic time for the a $\mathrm{\Lambda }\mathrm{CDM}$ solution and suffers a slight shift (advances slower) with respect to the cosmic time in the region close to the bounce for the bouncing nonsingular solutions. In addition, we introduce some exponential potential which could enter into the $T_{(\chi )}^{\mu \nu }$ stress energy tensor or be coupled directly to the measure $\sqrt{-g}$, giving a possible interaction between dark energy and dark matter, and could explain the coincidence problem.

Gravitinos are a fundamental prediction of supergravity, their mass ($m_G$) is informative of the value of the SUSY breaking scale, and, if produced during reheating, their number density is a function of the reheating temperature ($T_{\mathrm{rh}}$). As a result, constraining their parameter space provides, in turn, significant constraints on particle physics and cosmology. We have previously shown that for gravitinos decaying into photons or charged particles during the ($\mu$ and $y$) distortion eras, upcoming CMB spectral distortions bounds are highly effective in constraining the $T_{\mathrm{rh}}-m_G$ space. For heavier gravitinos (with lifetimes shorter than a few $\times {10}^6\sec$), distortions are quickly thermalized and energy injections cause a temperature rise for the CMB bath. If the decay occurs after neutrino decoupling, its overall effect is a suppression of the effective number of relativistic degrees of freedom ($N_{\mathrm{eff}}$). In this paper, we utilize the observational bounds on $N_{\mathrm{eff}}$ to constrain gravitino decays and, hence, provide new constraints on gravitinos and reheating. For gravitino masses less than $\approx {10}^5\mathrm{GeV}$, current observations give an upper limit on the reheating scale in the range of $\approx 5\times {10}^{10}–5\times {10}^{11}\mathrm{GeV}$. For masses greater than $\approx 4\times {10}^3\mathrm{GeV}$, this can be more stringent than previous bounds from BBN constraints, coming from photodissociation of deuterium, by almost 2 orders of magnitude.

Recently, we proposed an optically pumped five-level gain with electromagnetically induced transparency system, which has a transparency dip superimposed on a gain profile and exhibits a negative dispersion suitable for the white light cavity enhanced interferometric gravitational-wave detector [Phys. Rev. D 92, 082002 (2015)]. Using this system as the negative dispersion medium in the white light cavity signal-recycling scheme, we get an enhancement in the quantum noise limited sensitivity–bandwidth product by a factor of $\sim 18$. We have also shown how to realize such a system in practice using Zeeman sublevels in ${}^{87}\mathrm{Rb}$ at 795 nm [Opt. Commun. 402, 382 (2017)]. However, the Advanced Laser Interferometric Gravitational-Wave Observatory (aLIGO) operates at 1064 nm, and suitable transitions in Rb or other alkali atoms are not available at this wavelength. Therefore, it is necessary to consider a system that is consistent with the operating wavelength of aLIGO. Here, we present the realization of such a negative dispersion medium at 1064 nm with a microresonator, which supports optomechanical interaction. A strong control field is applied at a higher frequency, and, under certain conditions, a probe field at a lower frequency experiences a peak at the center of an absorption profile and a negative dispersion in the transmission. Unlike in the gain with electromagnetically induced transparency case, we use the compound-cavity signal-recycling scheme, in which an auxiliary mirror is inserted in the dark port of the detector, and show that the enhancement factor can be as high as $\sim 15$. However, using the parameters required for the sensitivity enhancement, the optomechanical system enters an instability region where the control field is depleted. We present an observer-based feedback control process used to stabilize the system.

We perform a complete calculation of electron-seeded pair creation (the trident process) in a constant crossed electromagnetic background. Unlike earlier treatments, we include the interference between exchange diagrams. We find that this exchange interference can be written as a contribution solely to the one-step process, and for small quantum nonlinearity parameter is of the same order as other one-step terms. We find that the exchange interference further suppresses the one-step process in this parameter regime. Our findings further support the crucial assumption made in laser-plasma simulation codes that at high intensities, the trident process can be well approximated by the repeated iteration of the single-vertex subprocesses. The applicability of this assumption to higher-vertex processes has fundamental importance to the development of simulation capabilities.

We study the lepton flavor models, whose flavor symmetries are finite subgroups of the modular group such as $S_3$ and $A_4$. In our models, couplings are also nontrivial representations of these groups and modular functions of the modulus. We study the possibilities that these models realize realistic values of neutrino masses and lepton mixing angles.

We consider the dynamics of gauge-Yukawa theories in the presence of a large number of matter constituents. We first review the current status for the renormalization group equations of gauge-fermion theories and extend the results to semisimple groups. In this regime these theories develop an interacting ultraviolet fixed point that for the semisimple case leads to a rich phase diagram. The latter contains a complete asymptotically safe fixed point repulsive in all couplings. We then add two gauged Weyl fermions belonging to arbitrary representations of the semisimple gauge group and a complex, gauged scalar to the original gauge-fermion theory allowing for new Yukawa interactions and quartic scalar self-coupling. Consequently, we determine the first nontrivial order in $1/N_f$ for the Yukawa and quartic beta functions. Our work elucidates, consolidates, and extends results obtained earlier in the literature. We also acquire relevant knowledge about the dynamics of gauge-Yukawa theories beyond perturbation theory. Our findings are applicable to any extension of the standard model featuring a large number of fermions such as asymptotic safety.

The discovery of the Higgs boson at $\sim 125\mathrm{GeV}$ indicates that the scale of weak scale supersymmetry is higher than what was perceived in the pre-Higgs boson discovery era and lies in the several TeV region. This makes the discovery of supersymmetry more challenging and argues for hadron colliders beyond LHC at $\sqrt{s}=14\mathrm{TeV}$. The Future Circular Collider (FCC) study at CERN is considering a 100 TeV collider to be installed in a 100 km tunnel in the Lake Geneva basin. Another 100 km collider being considered in China is the Super proton-proton Collider. A third possibility recently proposed is the high-energy LHC (HE-LHC) which would use the existing CERN tunnel but achieve a center-of-mass energy of 28 TeV by using FCC magnet technology at significantly higher luminosity than at the high luminosity LHC (HL-LHC). In this work we investigate the potential of HE-LHC for the discovery of supersymmetry. We study a class of supergravity unified models under the Higgs boson mass and the dark matter relic density constraints and compare the analysis with the potential reach of the HL-LHC. A set of benchmarks is presented which are beyond the discovery potential of HL-LHC but are discoverable at HE-LHC. For comparison, we study model points at HE-LHC which are also discoverable at HL-LHC. For these model points, it is found that their discovery would require a HL-LHC run between 5–8 years while the same parameter points can be discovered in a period of a few weeks to $\sim 1.5\mathrm{yr}$ at HE-LHC running at its optimal luminosity of $2.5\times {10}^{35}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$. The analysis indicates that the HE-LHC possibility should be seriously pursued as it would significantly increase the discovery reach for supersymmetry beyond that of HL-LHC and decrease the run period for discovery.