General relativity can be formulated equivalently with a non-Riemannian geometry that associates with an affine connection of nonzero nonmetricity $Q$ but vanishing curvature $R$ and torsion $T$. Modification based on this description of gravity generates the $f(Q)$ gravity. In this work, we explore the application of $f(Q)$ gravity to the spherically symmetric configurations. We discuss the gauge fixing and connections in this setting. We demonstrate the effects of $f(Q)$ by considering the external and internal solutions of compact stars. The external background solutions for any regular form of $f(Q)$ coincide with the corresponding solutions in general relativity, i.e., the Schwarzschild–de Sitter solution and the Reissner–Nordström–de Sitter solution with an electromagnetic field. For internal structure, with a simple model $f(Q)=Q+\alpha Q^2$ and a polytropic equation of state, we find that a negative modification ($\alpha <0$) provides support to more stellar masses while a positive one ($\alpha >0$) reduces the amount of matter of the star.

We analyze the early stage of evolution of a universe with two scale factors proposed in Falomir et al. [Phys. Rev. D 96, 083534 (2017)]. when matter is present. The scale factors describe two causally disconnected patches of the universe interacting trough a nontrivial Poisson bracket structure in the momentum sector characterized by one parameter $\kappa$. We studied two scenarios in which one of the patches is always filled with relativistic matter while the other contains relativistic matter in one case, and nonrelativistic matter in the second case. By solving numerically the set of equations governing the dynamics, we found that the energy content of one sector drains to the other and from here it is possible to constrain the deformation parameter $\kappa$ by supposing that the decay of the energy density happens, at most, at the Big Bang Nucleosynthesis temperature in order to return to the usual behavior of radiation. The relation with nonstandard cosmologies is also addressed.

We propose a novel method to detect cosmic magnification signals by cross-correlating foreground convergence fields constructed from galaxy shear measurements with background galaxy positional distributions—namely, shear-number density correlation. We apply it to the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey data. With 27 nonindependent data points and their full covariance, ${\chi }_0^2\approx 34.1$ and ${\chi }_T^2\approx 24.0$ with respect to the null and the cosmological model with the parameters from HSC shear correlation analyses in Hamana et al. [Publ. Astron. Soc. Jpn. 72, 16 (2020)], respectively. The Bayes factor of the two is ${\log }_{10}{B}_{T0}\approx 2.2$ assuming equal model probabilities of null and HSC cosmology, showing a clear detection of the magnification signals. Theoretically, the ratio of the shear-number density and shear-shear correlations can provide a constraint on the effective multiplicative shear bias $\overline{m}$ using internal data themselves. We demonstrate the idea with the signals from our HSC-SSP mock simulations and rescale the statistical uncertainties to a survey of $15000{\mathrm{deg}}^2$. For two-bin analyses with background galaxies brighter than $m_{\lim }=23$, the combined analyses lead to a forecasted constraint of $\sigma (\overline{m})\sim 0.032$, 2.3 times tighter than that found when using the shear-shear correlation alone. Correspondingly, $\sigma (S_8)$ with $S_8={\sigma }_8({\mathrm{\Omega }}_{\mathrm{m}}/0.3{)}^{0.5}$ is tightened by $\sim 2.1$ times. Importantly, the joint constraint on $\overline{m}$ is nearly independent of cosmological parameters. Our study therefore points to the importance of including the shear-number density correlation in weak lensing analyses, which can provide valuable consistency tests of observational data, and thus to solidify the derived cosmological constraints.

A nonperturbative determination of the energy-momentum tensor is essential for understanding the physics of strongly coupled systems. The ability of the Wilson flow to eliminate divergent contact terms makes it a practical method for renormalizing the energy-momentum tensor on the lattice. In this paper, we utilize the Wilson flow to define a procedure to renormalize the energy-momentum tensor for a three-dimensional massless scalar field in the adjoint of $SU(N)$ with a ${\phi }^4$ interaction on the lattice. In this theory the energy-momentum tensor can mix with ${\phi }^2$ and we present numerical results for the mixing coefficient for the $N=2$ theory.

Inspired by the discovery of the spin-$\frac{1}{2}$ doubly charmed baryon ${\mathrm{\Xi }}_{cc}^{++}$ and the subsequent theoretical studies of its magnetic moments, we study the magnetic moments of its spin-$\frac{3}{2}$ heavy quark spin symmetry counterparts, up to the next-to-leading order in covariant baryon chiral perturbation theory with the extended-on-mass-shell renormalization scheme. With the tree-level contributions fixed by the quark model while the two low energy constants $C$ and $H$ controlling the loop contributions determined in two ways: the quark model (case 1) and lattice QCD simulations together with the quark model (case 2), we study the quark mass dependence of the magnetic moments and compare them with the predictions of the heavy baryon chiral perturbation theory. It is shown that the difference is sizable in case 1, but not in case 2 due to the smaller low energy constants $C$ and $H$, similar to the case of spin-$\frac{1}{2}$ doubly charmed baryons. Second, we predict the magnetic moments of the spin-$\frac{3}{2}$ doubly charmed baryons and compare them with those of other approaches. The predicted magnetic moments in case 2 for the spin-$\frac{3}{2}$ doubly charmed baryons are closer to those of other approaches. In addition, the large differences in case 1 and case 2 for the predicted magnetic moments may indicate the inconsistency between the quark model and the lattice QCD simulations, which should be checked by future experimental or more lattice QCD data.

Using the entire data sample of $980\mathrm{f}{\mathrm{b}}^{-1}$ integrated luminosity collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider, we present an amplitude analysis measuring the branching fractions of the Cabibbo-allowed, $W$-exchange resonant decay ${\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^0\varphi (\to K^{+}{K}^{-})$ with a polarized $\varphi$ and the nonresonant decay via a direct process ${\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^0{K}^{+}{K}^{-}$. We present these measurements, relative to the normalization mode ${\mathrm{\Xi }}^{-}{\pi }^{+}$, and find branching ratios $\frac{\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^0\varphi (\to K^{+}{K}^{-}))}{(\mathcal{B}{\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})}=0.036\pm 0.004(\mathrm{stat}.)\pm 0.002(\mathrm{syst}.)$ and $\frac{\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^0{K}^{+}{K}^{-})}{\mathcal{B}({\mathrm{\Xi }}_c^0\to {\mathrm{\Xi }}^{-}{\pi }^{+})}=0.039\pm 0.004(\mathrm{stat}.)\pm 0.002(\mathrm{syst}.)$, which suggest that only minor cusping peaks occur in the combinatorial background of ${\mathrm{\Omega }}^{*-}\to {\mathrm{\Xi }}^0{K}^{-}$ due to these ${\mathrm{\Xi }}_c^0$ decays.

We present a supersymmetric solution to the strong $CP$ problem based on spontaneous $CP$ violation which simultaneously addresses the effects coming from supersymmetry breaking. The generated $CP$ violating phase is communicated to the quark sector by interacting with a heavy quark a la Nelson-Barr. The Majorana mass of the right handed neutrinos is generated by interactions with the $CP$ violating sector and so does not conserve $CP$. This gives the neutrino sector a nontrivial $CP$ violating phase which can then generate the baryon asymmetry of the universe through leptogeneis. The problematic phase in the supersymmetry breaking parameters are suppressed by appealing to a particular gauge mediation model which naturally suppresses the phases of the tree-level gluino mass and Higgs bilinear masses. This suppression plus the fact that in gauge mediation all loop generated flavor and $CP$ violation is of the minimal flavor violation variety allows for a complete and consistent solution to the strong $CP$ problem.

Eigenvalues are defined for any element of an algebra of observables and do not require a representation in terms of wave functions or density matrices. A systematic algebraic derivation based on moments is presented here for the harmonic oscillator, together with a perturbative treatment of anharmonic systems. In this process, a collection of inequalities is uncovered which amount to uncertainty relations for higher-order moments saturated by the harmonic-oscillator excited states. Similar saturation properties hold for anharmonic systems order by order in perturbation theory. The new method, based on recurrence relations for moments of a state combined with positivity conditions, is therefore able to show new physical features.

We consider the higher order clockwork theory of gravitational interactions, whereby a number of gravitons are coupled together with TeV strength, but nevertheless generate a Planck scale coupling to matter without the need for a dilaton. It is shown that the framework naturally lends itself to a five-dimensional geometry, and we find the 5D continuum version of such deconstructed 4D gravitational clockwork models. Moreover, the clockwork picture has matter coupled to particular gravitons, which in the 5D framework looks like a braneworld model, with the Randall-Sundrum model being a special case. More generally, the gravitational clockwork leads to a family of scalar-tensor braneworld models, where the scalar is not a dilaton.

Dark matter (DM) scattering and its subsequent capture in the Sun can boost the local relic density, leading to an enhanced neutrino flux from DM annihilations that is, in principle, detectable at neutrino telescopes. We calculate the event rates expected for a radiative seesaw model containing both scalar triplet and singlet-doublet fermion DM candidates. In the case of scalar DM, the absence of a spin dependent scattering on nuclei results in a low capture rate in the Sun, which is reflected in an event rate of less than one per year in the current IceCube configuration with 86 strings. For singlet-doublet fermion DM, there is a spin dependent scattering process next to the spin independent one, which significantly boosts the event rate and thus makes indirect detection competitive with respect to the direct detection limits imposed by pico-60. Because of a correlation between both scattering processes, the limits on the spin independent cross section set by xenon1t exclude also parts of the parameter space that can be probed at IceCube. Previously obtained limits by antares, IceCube, and super-kamiokande from the Sun and the Galactic Center are shown to be much weaker.

An excess of $\gamma$ rays in the data measured by the Fermi Large Area Telescope in the direction of the Galactic Center has been reported in several publications. This excess, labeled as the Galactic Center excess (GCE), is detected analyzing the data with different interstellar emission models, point source catalogs and analysis techniques. The characteristics of the GCE, recently measured with unprecedented precision, are all compatible with dark matter particles (DM) annihilating in the main halo of our Galaxy, even if other interpretations are still not excluded. We investigate the DM candidates that fit the observed GCE spectrum and spatial morphology. We assume a simple scenario with DM annihilating into a single channel but we inspect also more complicated models with two and three channels. We perform a search for a $\gamma$-ray flux from a list of 48 Milky Way dwarf spheroidal galaxies (dSphs) using state-of-the-art estimation of the DM density in these objects. Since we do not find any significant signal from the dSphs, we put upper limits on the annihilation cross section that result to be compatible with the DM candidate that fits the GCE. However, we find that the GCE DM signal is excluded at the 95% confidence level by the AMS-02 $\overline{p}$ flux data for all purely hadronic (semihadronic) channels unless the diffusive halo size $L$ is smaller than 1.7 kpc (2.6 kpc). Such a small diffusion halo is at the $2\sigma$ significance lower limit for the results inferred from fluxes of radioactive cosmic rays and is in some tension with results from analyses performed with radio and $\gamma$-ray data. Furthermore, AMS-02 $e^{+}$ data rule out the GCE DM interpretation with pure or partial annihilation into $e^{+}{e}^{-}$. The only DM candidate that fits the GCE spectrum and fulfills all constraints obtained with the combined dSphs analysis and the AMS-02 $\overline{p}$ and $e^{+}$ data annihilates purely (or very dominantly) into ${\mu }^{+}{\mu }^{-}$, has a mass of $\sim 60\mathrm{GeV}$ and roughly a thermal cross section.

Current long-baseline neutrino-oscillation experiments such as $\mathrm{NO}\nu \mathrm{A}$ and T2K are mainly sensitive to physics in the neighborhood of the first oscillation maximum of the ${\nu }_{\mu }\to {\nu }_e$ oscillation probability. The future Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band beam tune optimized for $CP$-violation sensitivity that fully covers the region of the first maxima and part of the second. In the present study, we elucidate the role of second oscillation maximum in addressing issues pertaining to unknowns in the standard three-flavor paradigm. We consider a new DUNE beam tune optimized for coverage of the region of the second oscillation maxima which could be realized using proposed accelerator upgrades that provide multimegawatts of power at proton energies of 8 GeV. We find that the addition of the multimegawatt 8 GeV beam to DUNE wide-band running leads to modest improvement in sensitivity to $CP$ violation, mass hierarchy, and the octant of ${\theta }_{23}$ as well as the resolution of $\delta$ and the Jarlskog invariant. Significant improvements to the DUNE neutrino energy resolution yield a much larger improvement in performance. We conclude that the standard DUNE wide-band beam when coupled with excellent detector resolution capabilities is sufficient to resolve $\delta$ to better than $\sim 12°$ for all values of $\delta$ in a decade of running. For second maxima (8 GeV, 3 MW) beam running concurrently with the standard wide-band (80 GeV, 2.2 MW) beam for five of the 10 years, it is found that $\delta$ can be further resolved better than $\sim 10°$ for all values of $\delta$.

We compute the collisional energy loss of an energetic massive fermion crossing a chiral plasma at finite temperature characterized by an imbalance between the populations of left-handed and right-handed fermions. We find a new contribution to the energy loss which is proportional to the helicity of the test fermion and depends on the amount of chiral imbalance in the plasma. We then compute the difference between the energy loss of a fermion with the two opposite helicities, to assess whether this could be used to quantify the chiral imbalance in the plasma. We find that the leading contribution to these helicity-dependent energy loss contributions comes from the exchange of hard photons (or gluons for QCD) with the medium constituents, and in some scenarios can become comparable to the leading-order result for a plasma without any chiral imbalance. We also evaluate the contribution arising from soft photon exchange, which is a subleading effect, and requires regularization. We illustrate how dimensional regularization is a well suited prescription to be applied to these energy loss computations.

Effective field theory techniques provide us important tools to probe for physics beyond the Standard Model in a relatively model-independent way. In this work, we revisit the $CP$-even dimension-6 purely gluonic operator to investigate the possible constraints on it by studying its effect on top-pair production at the LHC, in particular the high $p_T$ and $m_{t\overline{t}}$ tails of the distribution. Cut-based analysis reveals that the scale of new physics when this operator alone contributes to the production process is greater than 3.6 TeV at 95% C.L., which is a much stronger bound compared to the bound of 850 GeV obtained from Run-I data using the same channel. This is reinforced by an analysis using machine learning techniques. Our study complements similar studies that have focused on other collider channels to study this operator.

We examine the cosmological and astrophysical signatures of a “dark baryon,” a neutral fermion that mixes with the neutron. As the mixing is through a higher-dimensional operator at the quark level, production of the dark baryon at high energies is enhanced so that its abundance in the early universe may be significant. Treating its initial abundance as a free parameter, we derive new, powerful limits on the properties of the dark baryon. Primordial nucleosynthesis and the cosmic microwave background provide strong constraints due to the interconversion of neutrons to dark baryons through their induced transition dipole, and due to late decays of the dark baryon. Additionally, neutrons in a neutron star could decay slowly to dark baryons, providing a novel source of heat that is constrained by measurements of pulsar temperatures. Taking all the constraints into account, we identify parameter space where the dark baryon can be a viable dark matter candidate and discuss promising avenues for probing it.

Previously, the Einstein equation has been described as an equation of state, general relativity as the equilibrium state of gravity, and $f(\mathcal{R})$ gravity as a nonequilibrium one. We apply Eckart’s first order thermodynamics to the effective dissipative fluid describing scalar-tensor gravity. Surprisingly, we obtain simple expressions for the effective heat flux, “temperature of gravity”, shear and bulk viscosity, and entropy density, plus a generalized Fourier law in a consistent Eckart thermodynamical picture. Well-defined notions of temperature and approach to equilibrium, missing in the current thermodynamics of spacetime scenarios, naturally emerge.

We formulate a version of the information paradox in de Sitter spacetime and show that it is solved by the emergence of entanglement islands in the context of the De Sitter/de Sitter correspondence; in particular, the entanglement entropy of a subregion obeys a time-dependent Page curve. Our construction works in general spacetime dimensions and keeps the graviton massless. We interpret the resulting behavior of the entanglement entropy using double holography. It suggests that the spatial distribution of microscopic degrees of freedom depends on descriptions, as in the case of a black hole. In the static (distant) description of de Sitter (black hole) spacetime, these degrees of freedom represent microstates associated with the Gibbons-Hawking (Bekenstein-Hawking) entropy and are localized toward the horizon. On the other hand, in a global (effective two-sided) description, which is obtained by the quantum analog of analytic extension and is intrinsically semiclassical, they are distributed uniformly and in a unique semiclassical de Sitter (black hole) vacuum state.

We consider the matrix regularization of scalar fields on a Riemann surface with a general gauge-field background. We propose a construction of the fuzzy version of the Laplacian.

We investigate the relations between bit thread, entanglement distillation, and entanglement of purification in the holographic framework. Specifically, we give a bit thread interpretation for the one-shot entanglement distillation (OSED) tensor network, which can be understood as reconstructing the geometric structure of the bulk spacetime from the entanglement information of the boundary quantum system through the “surface growth scheme.” Moreover, by showing that the holographic entanglement of purification (EoP) process can be regarded as a special case of our “surface growth scheme,” we naturally obtain the bit thread interpretation of the holographic EoP in our framework, which turns out to be different from the existing interpretations. Since our interpretation for holographic EoP is obtained in a more general and physical framework, the advantage of our version is that it is more natural, and possibly more reasonable, to reflect the real physical entanglement structures.

We derive global consistency condition for strongly coupled heterotic string in the presence of M5-branes. Its elliptic genus is interpretable as generating functional of anomaly polynomials and so, on anomaly-free vacua, the genus is both holomorphic and modular invariant. In the holomorphic basis, we identify the modular properties by calculating the phase. By interpreting the refinement parameters as background curvature of tangent and vector bundles, we show that the extended Bianchi identity for Kalb–Ramond field of heterotic M-theory is satisfied in the presence of arbitrary numbers of M5-branes.