We consider models of extended gravity and in particular, generic models containing scalar-tensor and higher-order curvature terms, as well as a model derived from noncommutative spectral geometry. Studying, in the weak-field approximation (the Newtonian and post-Newtonian limit of the theory), the geodesic and Lense-Thirring processions, we impose constraints on the free parameters of such models by using the recent experimental results of the Gravity Probe B (GPB) and Laser Relativity Satellite (LARES) satellites. The imposed constraint by GPB and LARES is independent of the torsion-balance experiment, though it is much weaker.

The accelerating expansion of the universe at recent epochs is encoded in the cosmic microwave background: a few percent of the total temperature fluctuations are generated by evolving gravitational potentials which trace the large-scale structures in the universe. This signature of dark energy, the integrated Sachs-Wolfe effect, has been detected by averaging temperatures in the Wilkinson Microwave Anisotropy Probe (WMAP) sky maps corresponding to the directions of superstructures in the Sloan Digital Sky Survey data release 6. We model the maximum average peak signal expected in the standard $\mathrm{\Lambda }\mathrm{CDM}$ cosmological model, using Gaussian random realizations of the microwave sky, including correlations between different physical contributions to the temperature fluctuations and between different redshift ranges of the evolving gravitational potentials. We find good agreement with the mean temperature peak amplitude from previous theoretical estimates based on large-scale structure simulations, but with larger statistical uncertainties. We apply our simulation pipeline to four different foreground-cleaned microwave temperature maps from Planck and WMAP data, finding a mean temperature peak signal at previously identified sky locations which exceeds our theoretical mean signal at a statistical significance of about $2.5\sigma$ and which differs from a null signal at $3.5\sigma$.

The generation of large-scale magnetic fields in inflationary cosmology is explored, in particular, in a kind of moduli inflation motivated by racetrack inflation in the context of the type IIB string theory. In this model, the conformal invariance of the hypercharge electromagnetic fields is broken thanks to the coupling of both the scalar and pseudoscalar fields to the hypercharge electromagnetic fields. The following three cosmological observable quantities are first evaluated: the current magnetic field strength on the Hubble horizon scale, which is much smaller than the upper limit from the backreaction problem, local non-Gaussianity of the curvature perturbations due to the existence of the massive gauge fields, and the tensor-to-scalar ratio. It is explicitly demonstrated that the resultant values of local non-Gaussianity and the tensor-to-scalar ratio are consistent with the Planck data.

Stationary, asymptotically flat spacetimes in general relativity can be characterized by their multipole moments. The moments have proved to be very useful tools for extracting information about the spacetime from various observables and, more recently, for establishing universalities in the structure of neutron stars. As a first step toward extending these methods beyond general relativity, we develop the formalism that allows one to define and calculate the multipole moment in scalar-tensor theories of gravity.

We study analytically the time-dependent boundary conditions of superconducting microwave circuit experiments in the high plasma frequency limit, in which the conditions are Robin-type and relate the value of the field to the spatial derivative of the field. We give an explicit solution to the field evolution for boundary condition modulations that are small in magnitude but may have arbitrary time dependence, in a formalism that applies both to a semiopen waveguide and to a closed waveguide with two independently adjustable boundaries. The correspondence between the microwave Robin boundary conditions and the mechanically moving Dirichlet boundary conditions of the dynamical Casimir effect is shown to break down at high field frequencies, approximately 1 order of magnitude above the frequencies probed in the 2011 experiment of Wilson et al. Our results bound the parameter regime in which a microwave circuit can be used to model relativistic effects in a mechanically moving cavity, and they show that beyond this parameter regime moving mirrors produce more particles and generate more entanglement than their nonmoving microwave waveguide simulations.

It is proposed to use exact, cosmologically relevant solutions to Einstein’s equations to accurately quantify the precision of ray tracing techniques through Newtonian $N$-body simulations. As an initial example of such a study, the recipe in (Green and Wald, 2012) for going between $N$-body results and a perturbed Friedmann-Lemaitre-Robertson-Walker (FLRW) metric in the Newtonian gauge is used to study light propagation through quasispherical Szekeres models. The study is conducted by deriving a set of ordinary differential equations (ODEs) giving an expression for the angular diameter distance in the Newtonian gauge metric. The accuracy of the results obtained from the ODEs is estimated by using the ODEs to determine the distance-redshift relation in mock $N$-body data based on quasispherical Szekeres models. The results are then compared to the exact relations. From this comparison it is seen that the obtained ODEs can accurately reproduce the distance-redshift relation along both radial and nonradial geodesics in spherically symmetric models. The reproduction of geodesics in nonsymmetric Szekeres models is slightly less accurate, but still good. These results indicate that the employment of perturbed FLRW metrics for standard ray tracing techniques yields fairly accurate results, at least regarding distance-redshift relations. It is possible though, that this conclusion will be rendered invalid if other typical ray tracing approximations are included and if light is allowed to travel through several structures instead of just one.

The Advanced LIGO and Advanced Virgo gravitational-wave (GW) detectors will begin operation in the coming years, with compact binary coalescence events a likely source for the first detections. The gravitational waveforms emitted directly encode information about the sources, including the masses and spins of the compact objects. Recovering the physical parameters of the sources from the GW observations is a key analysis task. This work describes the LALInference software library for Bayesian parameter estimation of compact binary signals, which builds on several previous methods to provide a well-tested toolkit which has already been used for several studies. We show that our implementation is able to correctly recover the parameters of compact binary signals from simulated data from the advanced GW detectors. We demonstrate this with a detailed comparison on three compact binary systems: a binary neutron star, a neutron star–black hole binary and a binary black hole, where we show a cross comparison of results obtained using three independent sampling algorithms. These systems were analyzed with nonspinning, aligned spin and generic spin configurations respectively, showing that consistent results can be obtained even with the full 15-dimensional parameter space of the generic spin configurations. We also demonstrate statistically that the Bayesian credible intervals we recover correspond to frequentist confidence intervals under correct prior assumptions by analyzing a set of 100 signals drawn from the prior. We discuss the computational cost of these algorithms, and describe the general and problem-specific sampling techniques we have used to improve the efficiency of sampling the compact binary coalescence parameter space.

Motivated by the Galactic Center gamma-ray excess in the Fermi-LAT data, we study the signatures of a class of tau portal dark matter (DM) models where DM particles preferentially couple to tau leptons at the LHC. We consider the constraints from the DM direct detection and investigate the sensitivity of the LHC to di-tau plus missing energy signatures. We find that the LHC with a high luminosity of $3000{\mathrm{fb}}^{-1}$ can test the tau portal DM models with fermionic mediators in the mass range of $120\sim 450\mathrm{GeV}$.

Using $482{\mathrm{pb}}^{-1}$ of data taken at $\sqrt{s}=4.009\mathrm{GeV}$, we measure the branching fractions of the decays of $D^{*0}$ into $D^0{\pi }^0$ and $D^0\gamma$ to be $\mathcal{B}(D^{*0}\to D^0{\pi }^0)=(65.5\pm 0.8\pm 0.5)\%$ and $\mathcal{B}(D^{*0}\to D^0\gamma )=(34.5\pm 0.8\pm 0.5)\%$, respectively, by assuming that the $D^{*0}$ decays only into these two modes. The ratio of the two branching fractions is $\mathcal{B}(D^{*0}\to D^0{\pi }^0)/\mathcal{B}(D^{*0}\to D^0\gamma )=1.90\pm 0.07\pm 0.05$, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of 3 compared to the present world average values.

A method is presented for deducing classical point-particle Lagrange functions corresponding to a class of quartic dispersion relations. Applying this to particles violating Lorentz symmetry in the minimal Standard-Model Extension leads to a variety of novel Lagrangians in flat spacetime. Morphisms in these classical systems are studied that echo invariance under field redefinitions in the quantized theory. The Lagrange functions found offer new possibilities for understanding Lorentz-breaking effects by exploring parallels with Finsler-like geometries.

The proximity of the MOND acceleration constant with cosmological accelerations—for example, $a_0\approx c{H}_0/2\pi$—points to its possibly decreasing with cosmic time. I begin to consider the secular changes induced in galactic systems by such presumed variations, which are assumed to be adiabatic. It is important to understand these effects, in isolation from other evolutionary influences, in order to identify or constrain $a_0$ variations by detection of induced effects, or lack thereof. I find that as long as the system is fully in the deep-MOND regime—as applies to many galactic systems—the adiabatic response of the system obeys simple scaling laws. For example, in a system that would be stationary for fixed $a_0$, the system expands homologously as $a_0^{-1/4}$, while internal velocities decrease uniformly as $a_0^{1/4}$. If $a_0\propto cH$ at all relevant times, this change amounts to a factor of $\sim 2.5$ since redshift 10. For rotating systems, the angular frequency $\mathrm{\Omega }\propto a_0^{1/2}$. The accelerations increase relative to $a_0$ as $a_0^{-1/4}$, pushing the system towards the Newtonian regime. All this follows from the appearance of $a_0$ in MOND and the scale invariance of the deep-MOND limit—two basic tenets of MOND. More complicated evolution ensues when parts of the system become Newtonian, or are so from inception. For example, these parts may become unstable since they are not protected by MOND’s stabilizing effects. The existence of such regions also modifies the MONDian regime since they affect the potential everywhere, and constituents might migrate between the Newtonian and MONDian regimes. Studying these last effects would require detailed numerical calculations.

We investigate the differential number counts of sources in radio continuum surveys, including all terms at linear order in cosmological perturbations. Our framework does not assume a specific gauge condition. This general approach allows us to recover gauge invariance explicitly. With the complete derivations of the covariant volume integral on the past light cone, we have identified several contributions in the number counts. To clarify their underlying physics, we present each contribution in terms of scalar, vector and tensor modes. This theoretical framework promises to be widely applicable to continuum radio galaxy surveys to model the expected angular power spectrum and two-point correlation.

Primordial non-Gaussianity of local type is known to produce a scale-dependent contribution to the galaxy bias. Several classes of multifield inflationary models predict non-Gaussian bias which is stochastic, in the sense that dark matter and halos do not trace each other perfectly on large scales. In this work, we forecast the ability of next-generation large-scale structure surveys to constrain common types of primordial non-Gaussianity like $f_{\mathrm{NL}}$, $g_{\mathrm{NL}}$ and ${\tau }_{\mathrm{NL}}$ using halo bias, including stochastic contributions. We provide fitting functions for statistical errors on these parameters which can be used for rapid forecasting or survey optimization. A next-generation survey with volume $V=25h^{-3}{\mathrm{Gpc}}^3$, median redshift $z=0.7$ and mean bias $b_g=2.5$ can achieve $\sigma (f_{\mathrm{NL}})=6$, $\sigma (g_{\mathrm{NL}})={10}^5$ and $\sigma ({\tau }_{\mathrm{NL}})={10}^3$ if no mass information is available. If halo masses are available, we show that optimally weighting the halo field in order to reduce sample variance can achieve $\sigma (f_{\mathrm{NL}})=1.5$, $\sigma (g_{\mathrm{NL}})={10}^4$ and $\sigma ({\tau }_{\mathrm{NL}})=100$ if halos with mass down to $M_{\min }={10}^{11}{h}^{-1}{M}_{\odot }$ are resolved, outperforming Planck by a factor of 4 on $f_{\mathrm{NL}}$ and nearly an order of magnitude on $g_{\mathrm{NL}}$ and ${\tau }_{\mathrm{NL}}$. Finally, we study the effect of photometric redshift errors and discuss degeneracies between different non-Gaussian parameters, as well as the impact of marginalizing Gaussian bias and shot noise.

Models of weakly interacting massive particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy-quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy $SU(2{)}_W\times U(1{)}_Y$ charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of $n_f=3$-flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order $v^2/c^2$ in the nonrelativistic nucleon effective theory are derived.

We present formalism necessary to determine weak-scale matching coefficients in the computation of scattering cross sections for putative dark matter candidates interacting with the Standard Model. We pay particular attention to the heavy-particle limit. A consistent renormalization scheme in the presence of nontrivial residual masses is implemented. Two-loop diagrams appearing in the matching to gluon operators are evaluated. Details are given for the computation of matching coefficients in the universal limit of WIMP-nucleon scattering for pure states of arbitrary quantum numbers, and for singlet-doublet and doublet-triplet mixed states.

Postulating the existence of a finite-mass mediator of T,P-odd coupling between atomic electrons and nucleons, we consider its effect on the permanent electric dipole moment (EDM) of diamagnetic atoms. We present both numerical and analytical analysis for such mediator-induced EDMs and compare it with EDM results for the conventional contact interaction. Based on this analysis, we derive limits on coupling strengths and carrier masses from experimental limits on EDM of the ${}^{199}\mathrm{Hg}$ atom.

Leptoquarks with mass in the region of 550–650 GeV are a possible candidate for the recent excess seen by CMS in the $eejj$ and $e\nu jj$ channels. We discuss models where leptoquarks decay primarily to dark matter and jets, thereby giving a branching to charged lepton and jet final states that can match data. The confluence of proton decay constraints, dark matter indirect and direct detection data, and Higgs invisible decay bounds results in a handful of predictive models that will be conclusively verified or excluded in upcoming direct detection experiments. Along the way, we present robust limits on such leptoquark models stemming from the muon magnetic moment using current and projected experiment sensitivities, as well as from $K$ and $B$ meson mixing, and leptonic and semileptonic meson decays.

We compute, via numerical simulations, the nonperturbative Coulomb potential of pure SU(3) gauge theory in Coulomb gauge. We find that the Coulomb potential scales nicely in accordance with asymptotic freedom, that the Coulomb potential is linear in the infrared, and that the Coulomb string tension is about four times larger than the asymptotic string tension. We explain how it is possible that the asymptotic string tension can be lower than the Coulomb string tension by a factor of four.

We calculate the triple- and quadruple-gluon inclusive distributions with arbitrary rapidity and azimuthal angle dependence in the gluon saturation regime by using glasma diagrams. Also, we predict higher-dimensional ridges in triple- and quadruple-hadron correlations for p–p and p–Pb collisions at LHC, which have yet to be measured. In p–p and p–Pb collisions at the top LHC energies, gluon saturation is expected to occur since smaller Bjorken-$x$ values are being probed. Glasma diagrams, which are enhanced at small-$x$, include gluon saturation effects, and they are used for calculating the long-range rapidity correlations (“ridges”) and $v_n$ moments of the azimuthal distribution of detected hadrons. The glasma description reproduces the systematics of the data on both p–p and p–Pb ridges. As an alternative, relativistic hydrodynamics has also been applied to these small systems quite successfully. With the triple- and quadruple-gluon azimuthal correlations, this work aims to set the stage by going beyond the double-gluon azimuthal correlations in order to settle unambiguously the origin of “collectivity” in p–p and p–Pb collisions. We derive the triple- and quadruple-gluon azimuthal correlation functions in terms of unintegrated gluon distributions at arbitrary rapidities and azimuthal angles of produced gluons. Then, unintegrated gluon distributions from the running coupling Balitsky-Kovchegov evolution equation are used to calculate the triple- and quadruple-gluon correlations for various parameters of gluon momenta, initial scale for small-$x$ evolution and beam energy.