@article{21125, abstract = {The thermal Sunyaev-Zel’dovich effect (tSZ) is a sensitive probe of cosmology, as it traces the abundance of galaxy clusters and groups in the late-time Universe. Upcoming cosmic microwave background experiments such as the Simons Observatory (SO) and CMB-S4 will provide low-noise and high-resolution component-separated tSZ maps covering a large sky fraction. The tSZ signal is highly non-Gaussian; therefore, higher-order statistics are needed to optimally extract information from these maps. In this work, we study the cosmological constraining power of several tSZ statistics—Minkowski functionals (MFs), peaks, minima, and moments—that have yielded promising results in capturing non-Gaussian information from other cosmological data. Using a large suite of halo-model-based tSZ simulations with varying Ω𝑐 and 𝜎8 (154 cosmologies and over 800,000 maps, each 10.5×10.5  deg2), we show that by combining these observables, we can achieve ≈29 × tighter constraints compared to using the tSZ power spectrum alone in an idealized noiseless case, with the MFs dominating the constraints. We show that much of the MF constraining power arises from halos below the detection threshold of cluster surveys, suggesting promising synergies with cluster-count analyses. Finally, we demonstrate that these statistics have the potential to deliver tight constraints even in the presence of noise. For example, using post-component-separation tSZ noise expected for SO, we obtain ≈1.6 × and ≈1.8 × tighter constraints than the power spectrum with MFs and all statistics combined, respectively. We show that the constraints from MFs approach the noiseless case for white-noise levels ≲1  𝜇⁢K−arcmin.}, author = {Sabyr, Alina and Hill, J. Colin and Haiman, Zoltán}, issn = {2470-0029}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society}, title = {{Constraining cosmology with thermal Sunyaev-Zel’dovich maps: Minkowski functionals, peaks, minima, and moments}}, doi = {10.1103/physrevd.111.103536}, volume = {111}, year = {2025}, } @article{21126, abstract = {Subparsec supermassive black hole (SMBH) binaries are expected to be common in active galactic nuclei as a result of the hierarchical buildup of galaxies via mergers. While direct evidence for these compact binaries is lacking, a few hundred candidates have been identified, most based on the apparent periodicities of their optical light curves. Since these signatures can be mimicked by active galactic nuclei red noise, additional evidence is needed to confirm their binary nature. Recurring self-lensing flares, occurring whenever the two BHs are aligned with the line of sight within their Einstein radii, have been suggested as additional binary signatures. Furthermore, in many cases, lensing flares are also predicted to contain a “dip,” whenever the lensed SMBH’s shadow is comparable in angular size to the binary’s Einstein radius. This feature would unambiguously confirm binaries and additionally identify SMBH shadows that are spatially unresolvable by high-resolution Very Long Baseline Interferometry (VLBI). Here we estimate the number of quasars for which these dips may be detectable by Legacy Survey of Space and Time (LSST) by extrapolating the quasar luminosity function to faint magnitudes and assuming that SMBH binaries are randomly oriented and have mass ratios following those in the Illustris simulations. Under plausible assumptions about quasar lifetimes, binary fractions, and Eddington ratios, we expect tens of thousands of detectable flares, of which several dozen contain measurable dips.}, author = {Park, Kevin and Xin, Chengcheng and Davelaar, Jordy and Haiman, Zoltán}, issn = {2470-0029}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, title = {{Self-lensing flares from black hole binaries. IV. The number of detectable shadows}}, doi = {10.1103/physrevd.111.063011}, volume = {111}, year = {2025}, } @article{20651, abstract = {The origin of merging binary black holes detected through gravitational waves remains a fundamental question in astrophysics. While stellar evolution imposes an upper mass limit of ∼50⁢𝑀⊙ for black holes, some observed mergers—most notably GW190521—involve significantly more massive components, suggesting alternative formation channels. Here we investigate the maximum masses attainable by black hole mergers within active galactic nucleus (AGN) disks. Using a comprehensive semianalytic model incorporating 27 binary and environmental parameters, we explore the role of AGN disk conditions in shaping the upper end of the black hole mass spectrum. We find that an AGN disk lifetime is the dominant factor, with high-mass mergers (≳200⁢𝑀⊙) only possible if disks persist for ≳40  Myr. The joint electromagnetic observation of an AGN-assisted merger could therefore lead to a direct measurement of the age of an AGN disk.}, author = {Xue, Ling Qin and Tagawa, Hiromichi and Haiman, Zoltán and Bartos, Imre}, issn = {2470-0029}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, title = {{What determines the maximum mass of AGN-assisted black hole mergers?}}, doi = {10.1103/5m1n-qh9v}, volume = {112}, year = {2025}, } @article{17545, abstract = {Self-lensing flares (SLFs) are expected to be produced once or twice per orbit by an accreting massive black hole binary (MBHB), if the eclipsing MBHBs are observed close to edge-on. SLFs can provide valuable electromagnetic (EM) signatures to accompany the gravitational waves (GWs) detectable by the upcoming Laser Interferometer Space Antenna (LISA). EM follow-ups are crucial for, e.g., sky-localization, and constraining the Hubble constant and the graviton mass. We use high-resolution two-dimensional viscous hydrodynamical simulations of a circumbinary disk (CBD) embedding a MBHB. We then use very high-cadence output of these hydrodynamical simulation inputs for a general-relativistic ray-tracing code to produce synthetic spectra and phase-folded light curves. Our main results show a significant periodic amplification of the flux with the characteristic shape of a sharp flare with a central dip, as the foreground black hole (BH) transits across the minidisk and shadow of the background BH, respectively. These corroborate previous conclusions based on the microlensing approximation and analytical toy models of the emission geometry. We also find that at lower inclinations, without some occlusion of the minidisk emission by the CBD, shocks from quasi-periodic mass-trading between the minidisks can produce bright flares which can mimic SLFs and could hinder their identification.}, author = {Krauth, Luke Major and Davelaar, Jordy and Haiman, Zoltán and Westernacher-Schneider, John Ryan and Zrake, Jonathan and MacFadyen, Andrew}, issn = {2470-0010}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society (APS)}, title = {{Self-lensing flares from black hole binaries: General-relativistic ray tracing of circumbinary accretion simulations}}, doi = {10.1103/physrevd.109.103014}, volume = {109}, year = {2024}, } @article{15198, abstract = {The axion-nucleon coupling enables the production of axions through the decay of excited 57Fe nuclei, and axions produced in the Sun through this process are often a target of helioscope searches. We show for the first time that hot, highly magnetic white dwarfs such as ZTF J1901+1458 are a viable target to search for the x-ray signature of axions that were produced by the 57Fe transition in the core and then converted to photons in the magnetosphere. We calculate that a 100 ks observation of ZTF J1901+1458 with NuSTAR would constrain the coupling of axions to nucleons and photons at a level below the bounds of both current and future planned helioscopes.}, author = {Fleury, Leesa and Caiazzo, Ilaria and Heyl, Jeremy}, issn = {2470-0029}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society}, title = {{Constraining axions with ZTF J1901+1458}}, doi = {10.1103/physrevd.107.l101303}, volume = {107}, year = {2023}, } @article{17526, abstract = {The self-lensing of a massive black hole binary (MBHB), which occurs when the two BHs are aligned close to the line of sight, is expected to produce periodic, short-duration flares. Here we study the shapes of self-lensing flares (SLFs) via general-relativistic ray tracing in a superimposed binary BH metric, in which the emission is generated by geometrically thin accretion flows around each component. The suite of models covers eccentric binary orbits, black hole spins, unequal mass binaries, and different emission model geometries. We explore the above parameter space and report how the light curves change as a function of, e.g., binary separation, inclination, and eccentricity. We also compare our light curves to those in the microlensing approximation, and show how strong deflections, as well as time-delay effects, change the size and shape of the SLF. If gravitational waves (GWs) from the inspiraling MBHB are observed by LISA, SLFs can help securely identify the source and localizing it on the sky, and to constrain the graviton mass by comparing the phasing of the SLFs and the GWs. Additionally, when these systems are viewed edge-on the SLF shows a distinct dip that can be directly correlated with the BH shadow size. This opens a new way to measure BH shadow sizes in systems that are unresolvable by current VLBI facilities.}, author = {Davelaar, Jordy and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society (APS)}, title = {{Self-lensing flares from black hole binaries: General-relativistic ray tracing of black hole binaries}}, doi = {10.1103/physrevd.105.103010}, volume = {105}, year = {2022}, } @article{17563, abstract = {In order to extract full cosmological information from next-generation large and high-precision weak lensing (WL) surveys (e.g., Euclid, Roman, and LSST), higher-order statistics that probe the small-scale, nonlinear regime of large-scale structure (LSS) need to be utilized. WL peak counts, which trace overdensities in the cosmic web, are one promising and simple statistic for constraining cosmological parameters. The physical origin of WL peaks have previously been linked to dark matter halos along the line of sight, and this peak-halo connection has been used to develop various semianalytic halo-based models for predicting peak counts. Here, we study the origin of WL peaks and the effectiveness of halo-based models for WL peak counts using a suite of ray-tracing N-body simulations. We compare WL peaks in convergence maps from the full simulations to those in maps created from only particles associated with halos—the latter playing the role of a “perfect” halo model. We find that, while halo-only contributions are able to replicate peak counts qualitatively well, halos do not explain all WL peaks. Halos particularly underpredict negative peaks, which are associated with local overdensities in large-scale underdense regions along the line of sight. In addition, neglecting nonhalo contributions to peaks counts leads to a significant bias on the parameters (Ωm, 𝜎8) for surveys larger than ⪆100  deg2. We conclude that other elements of the cosmic web, outside and far away from dark matter halos, need to be incorporated into models of WL peaks in order to infer unbiased cosmological constraints.}, author = {Sabyr, Alina and Haiman, Zoltán and Matilla, José Manuel Zorrilla and Lu, Tianhuan}, issn = {2470-0010}, journal = {Physical Review D}, number = {2}, publisher = {American Physical Society}, title = {{Cosmological constraints from weak lensing peaks: Can halo models accurately predict peak counts?}}, doi = {10.1103/physrevd.105.023505}, volume = {105}, year = {2022}, } @article{17582, abstract = {We use long-run, high-resolution hydrodynamics simulations to compute the multi-wavelength light curves (LCs) from thermal disk emission around accreting equal-mass supermassive black hole (BH) binaries, with a focus on revealing binary eccentricity. LCs are obtained by modeling the disk thermodynamics with an adiabatic equation of state, a local blackbody cooling prescription, and corrections to approximate the effects of radiation pressure. We find that modulation of multi-band LCs on the orbital time scale are generally in-phase (to within ∼2% of a binary orbital period), but they contain pulse substructure in the time domain that is not necessarily reflected in BH accretion rates M˙. We thus predict that binary-hosting AGN will exhibit highly correlated, in-phase, periodic brightness modulations in their low-energy disk emission. However, detectability of these modulations in multi-wavelength observing campaigns could be seriously compromised because observed stochastic variability in AGNs typically has a higher amplitude than our proposed signal. It is possible that observations over temporal baselines of many binary periods may make the signal more prominent, but this would need to be analyzed carefully. If jet emission is predicted by M˙, then we predict a weaker correlation with low-energy disk emission due to the differing sub-peak structure. For the binary parameters we explore, we show that LC variability due to hydrodynamics likely dominates Doppler brightening for all equal-mass binaries with disk Mach numbers ≲20. A promising signature of eccentricity is weak or absent "lump" periodicity. We find hints that a significant lag exists between M˙ and low-energy disk emission for circular binaries, but they are in-phase for eccentric binaries, which might explain some "orphan" blazar flares with no γ-ray counterpart.}, author = {Westernacher-Schneider, John Ryan and Zrake, Jonathan and MacFadyen, Andrew and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society}, title = {{Multiband light curves from eccentric accreting supermassive black hole binaries}}, doi = {10.1103/physrevd.106.103010}, volume = {106}, year = {2022}, } @article{17578, abstract = {If primordial black holes (PBHs) seeded the supermassive black holes (SMBHs) at the centers of high-redshift quasars, then the gas surrounding these black holes may reveal nucleosynthetic clues to their primordial origins. We present predictions of altered primordial abundances around PBHs massive enough to seed SMBHs at 𝑧≈6–7.5. We find that if PBHs with initial masses of ∼105  M⊙ are responsible for such SMBHs, they may produce primordial deuterium and Helium fractions enhanced by ≥10%, and lithium abundance depleted by ≥10%, at distances of up to ≈ a comoving kiloparsec away from the black hole after decoupling. We estimate that ∼108  M⊙ of gas is enhanced (or depleted) by at least one percent. Evidence of these modified primordial deuterium, helium, and lithium abundances could still be present if this circum-PBH gas remains unaccreted by the SMBH and in or near the host galaxies of high-redshift quasars. Measuring the abundance anomalies will be challenging, but could offer a novel way to reveal the primordial origin of such SMBH seeds.}, author = {Sanderbeck, Phoebe Upton and Bird, Simeon and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society}, title = {{Nucleosynthetic signatures of primordial origin around supermassive black holes}}, doi = {10.1103/physrevd.104.103022}, volume = {104}, year = {2021}, } @article{17591, abstract = {The rotational kinematic Sunyaev-Zeldovich (rkSZ) signal, imprinted on the cosmic microwave background (CMB) by the gaseous halos (spinning “atmospheres”) of foreground galaxies, would be a novel probe of galaxy formation. Although the signal is too weak to detect in individual galaxies, we analyze the feasibility of its statistical detection via stacking CMB data on many galaxies for which the spin orientation can be estimated spectroscopically. We use an “optimistic” model, in which fully ionized atmospheres contain the cosmic baryon fraction and spin at the halo’s circular velocity 𝑣circ, and a more realistic model, based on hydrodynamical simulations, with multiphase atmospheres spinning at a fraction of 𝑣circ. We incorporate realistic noise estimates into our analysis. Using low-redshift galaxy properties from the MaNGA spectroscopic survey (with median halo mass of 6.6×1011  𝑀⊙), and CMB data quality from Planck, we find that a 3⁢𝜎 detection would require a few×104 galaxies, even in the optimistic model. This is too high for current surveys, but upcoming higher-angular resolution CMB experiments will significantly reduce the requirements: stacking CMB data on galaxy spins in a ∼10 deg2 can rule out the optimistic models, and ≈350  deg2 will suffice for a 3⁢𝜎 detection with ACT. As a proof-of-concept, we stacked Planck data on the position of ≈2,000 MaNGA galaxies, aligned with the galaxies’ projected spin, and scaled to their halos’ angular size. We rule out average temperature dipoles larger than ≈1.9  𝜇⁢K around field spiral galaxies.}, author = {Matilla, José Manuel Zorrilla and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {8}, publisher = {American Physical Society}, title = {{Probing gaseous galactic halos through the rotational kinematic Sunyaev-Zeldovich effect}}, doi = {10.1103/physrevd.101.083016}, volume = {101}, year = {2020}, } @article{17597, abstract = {Deep Neural Networks (DNNs) are powerful algorithms that have been proven capable of extracting non-Gaussian information from weak lensing (WL) data sets. Understanding which features in the data determine the output of these nested, non-linear algorithms is an important but challenging task. We analyze a DNN that has been found in previous work to accurately recover cosmological parameters in simulated maps of the WL convergence (κ). We derive constraints on the cosmological parameter pair (Ωm,σ8) from a combination of three commonly used WL statistics (power spectrum, lensing peaks, and Minkowski functionals), using ray-traced simulated κ maps. We show that the network can improve the inferred parameter constraints relative to this combination by 20% even in the presence of realistic levels of shape noise. We apply a series of well established saliency methods to interpret the DNN and find that the most relevant pixels are those with extreme κ values. For noiseless maps, regions with negative κ account for 86−69% of the attribution of the DNN output, defined as the square of the saliency in input space. In the presence of shape nose, the attribution concentrates in high convergence regions, with 36−68% of the attribution in regions with κ>3σκ.}, author = {Matilla, José Manuel Zorrilla and Sharma, Manasi and Hsu, Daniel and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {12}, publisher = {American Physical Society}, title = {{Interpreting deep learning models for weak lensing}}, doi = {10.1103/physrevd.102.123506}, volume = {102}, year = {2020}, } @article{15238, abstract = {In the next decade, x-ray polarimetry will open a new window on the high-energy Universe, as several missions that include an x-ray polarimeter are currently under development. Observations of the polarization of x rays coming from the accretion disks of stellar-mass and supermassive black holes are among the new polarimeters’ major objectives. In this paper, we show that these observations can be affected by the quantum electrodynamic (QED) effect of vacuum birefringence: after an x-ray photon is emitted from the accretion disk, its polarization changes as the photon travels through the accretion disk’s magnetosphere, as a result of the vacuum becoming birefringent in the presence of a magnetic field. We show that this effect can be important for black holes in the energy band of the upcoming polarimeters and has to be taken into account in a complete model of the x-ray polarization that we expect to detect from black-hole accretion disks, both for stellar mass and for supermassive black holes. We find that, for a chaotic magnetic field in the disk, QED can significantly decrease the linear polarization fraction of edge-on photons, depending on the spin of the hole and on the strength of the magnetic field. This effect can provide, for the first time, a direct way to probe the magnetic field strength close to the innermost stable orbit of black-hole accretion disks and to study the role of magnetic fields in astrophysical accretion in general.}, author = {Caiazzo, Ilaria and Heyl, Jeremy}, issn = {2470-0029}, journal = {Physical Review D}, number = {8}, publisher = {American Physical Society}, title = {{Vacuum birefringence and the x-ray polarization from black-hole accretion disks}}, doi = {10.1103/physrevd.97.083001}, volume = {97}, year = {2018}, } @article{17662, abstract = {Weak lensing maps contain information beyond two-point statistics on small scales. Much recent work has tried to extract this information through a range of different observables or via nonlinear transformations of the lensing field. Here we train and apply a 2D convolutional neural network to simulated noiseless lensing maps covering 96 different cosmological models over a range of {Ωm,σ8}. Using the area of the confidence contour in the {Ωm,σ8} plane as a figure-of-merit, derived from simulated convergence maps smoothed on a scale of 1.0 arcmin, we show that the neural network yields ≈5× tighter constraints than the power spectrum, and ≈4× tighter than the lensing peaks. Such gains illustrate the extent to which weak lensing data encode cosmological information not accessible to the power spectrum or even other, non-Gaussian statistics such as lensing peaks.}, author = {Gupta, Arushi and Matilla, José Manuel Zorrilla and Hsu, Daniel and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {10}, publisher = {American Physical Society}, title = {{Non-Gaussian information from weak lensing data via deep learning}}, doi = {10.1103/physrevd.97.103515}, volume = {97}, year = {2018}, } @article{17673, abstract = {Accurate forward modeling of weak lensing (WL) observables from cosmological parameters is necessary for upcoming galaxy surveys. Because WL probes structures in the non-linear regime, analytical forward modeling is very challenging, if not impossible. Numerical simulations of WL features rely on ray-tracing through the outputs of N-body simulations, which requires knowledge of the gravitational potential and accurate solvers for light ray trajectories. A less accurate procedure, based on the Born approximation, only requires knowledge of the density field, and can be implemented more efficiently and at a lower computational cost. In this work, we use simulations to show that deviations of the Born-approximated convergence power spectrum, skewness and kurtosis from their fully ray--traced counterparts are consistent with the smallest non-trivial O(Φ3) post-Born corrections (so-called geodesic and lens-lens terms). Our results imply a cancellation among the larger O(Φ4) (and higher order) terms, consistent with previous analytic work. We also find that cosmological parameter bias induced by the Born approximated power spectrum is negligible even for an LSST-like survey, once galaxy shape noise is considered. When considering higher order statistics such as the κ skewness and kurtosis, however, we find significant bias of up to 2.5σ. Using the LensTools software suite, we show that the Born approximation saves a factor of 4 in computing time with respect to the full ray-tracing in reconstructing the convergence.}, author = {Petri, Andrea and Haiman, Zoltán and May, Morgan}, issn = {2470-0010}, journal = {Physical Review D}, number = {12}, publisher = {American Physical Society}, title = {{Validity of the Born approximation for beyond Gaussian weak lensing observables}}, doi = {10.1103/physrevd.95.123503}, volume = {95}, year = {2017}, } @article{17707, abstract = {The gravitational waves (GWs) from a binary black hole (BBH) with masses between 10^4 and 10^7 Msun can be detected with the Laser Interferometer Space Antenna (LISA) once their orbital frequency exceeds 10^-4 - 10^-5 Hz. The binary separation at this stage is approximately a=100 R_g (gravitational radius), and the orbital speed is of order v/c=0.1. We argue that at this stage, the binary will be producing bright electromagnetic (EM) radiation via gas bound to the individual BHs. Both BHs will have their own photospheres in X-ray and possibly also in optical bands. Relativistic Doppler modulations and lensing effects will inevitably imprint periodic variability in the EM light-curve, tracking the phase of the orbital motion, and serving as a template for the GW inspiral waveform. Advanced localization of the source by LISA weeks to months prior to merger will enable a measurement of this EM chirp by wide-field X-ray or optical instruments. A comparison of the phases of the GW and EM chirp signals will help break degeneracies between system parameters, and probe a fractional difference difference Delta v in the propagation speed of photons and gravitons as low as Delta v/c = O(10^-17).}, author = {Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {2}, publisher = {American Physical Society}, title = {{Electromagnetic chirp of a compact binary black hole: A phase template for the gravitational wave inspiral}}, doi = {10.1103/physrevd.96.023004}, volume = {96}, year = {2017}, } @article{17708, abstract = {We explore the sensitivity of weak lensing observables to the expansion history of the universe and to the growth of cosmic structures, as well as the relative contribution of both effects to constraining cosmological parameters. We utilize ray-tracing dark-matter-only N-body simulations and validate our technique by comparing our results for the convergence power spectrum with analytic results from past studies. We then extend our analysis to non-Gaussian observables which cannot be easily treated analytically. We study the convergence (equilateral) bispectrum and two topological observables, lensing peaks and Minkowski functionals, focusing on their sensitivity to the matter density Ωm and the dark energy equation of state w. We find that a cancelation between the geometry and growth effects is a common feature for all observables, and exists at the map level. It weakens the overall sensitivity by up to a factor of 3 and 1.5 for w and Ωm, respectively, with the bispectrum worst affected. However, combining geometry and growth information alleviates the degeneracy between Ωm and w from either effect alone. As a result, the magnitude of marginalized errors remain similar to those obtained from growth-only effects, but with the correlation between the two parameters switching sign. These results shed light on the origin of cosmology-sensitivity of non-Gaussian statistics, and should be useful in optimizing combinations of observables.}, author = {Matilla, José Manuel Zorrilla and Haiman, Zoltán and Petri, Andrea and Namikawa, Toshiya}, issn = {2470-0010}, journal = {Physical Review D}, number = {2}, publisher = {American Physical Society}, title = {{Geometry and growth contributions to cosmic shear observables}}, doi = {10.1103/physrevd.96.023513}, volume = {96}, year = {2017}, } @article{17712, abstract = {Multi-frequency gravitational wave (GW) observations are useful probes of the formation processes of coalescing stellar-mass binary black holes (BBHs). We discuss the phase drift in the GW inspiral waveform of the merging BBH caused by its center-of-mass acceleration. The acceleration strongly depends on the location where a BBH forms within a galaxy, allowing observations of the early inspiral phase of LIGO-like BBH mergers by the Laser Interferometer Space Antenna (LISA) to test the formation mechanism. In particular, BBHs formed in dense nuclear star clusters or via compact accretion disks around a nuclear supermassive black hole in active galactic nuclei would suffer strong acceleration, and produce large phase drifts measurable by LISA. The host galaxies of the coalescing BBHs in these scenarios can also be uniquely identified in the LISA error volume, without electromagnetic counterparts. A non-detection of phase drifts would rule out or constrain the contribution of the nuclear formation channels to the stellar-mass BBH population.}, author = {Inayoshi, Kohei and Tamanini, Nicola and Caprini, Chiara and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society }, title = {{Probing stellar binary black hole formation in galactic nuclei via the imprint of their center of mass acceleration on their gravitational wave signal}}, doi = {10.1103/physrevd.96.063014}, volume = {96}, year = {2017}, } @article{17626, abstract = {Weak gravitational lensing is becoming a mature technique for constraining cosmological parameters, and future surveys will be able to constrain the dark energy equation of state 𝑤. When analyzing galaxy surveys, redshift information has proven to be a valuable addition to angular shear correlations. We forecast parameter constraints on the triplet (Ω𝑚,𝑤,𝜎8) for a LSST-like photometric galaxy survey, using tomography of the shear-shear power spectrum, convergence peak counts and higher convergence moments. We find that redshift tomography with the power spectrum reduces the area of the 1⁢𝜎 confidence interval in (Ω𝑚,𝑤) space by a factor of 8 with respect to the case of the single highest redshift bin. We also find that adding non-Gaussian information from the peak counts and higher-order moments of the convergence field and its spatial derivatives further reduces the constrained area in (Ω𝑚,𝑤) by factors of 3 and 4, respectively. When we add cosmic microwave background parameter priors from Planck to our analysis, tomography improves power spectrum constraints by a factor of 3. Adding moments yields an improvement by an additional factor of 2, and adding both moments and peaks improves by almost a factor of 3 over power spectrum tomography alone. We evaluate the effect of uncorrected systematic photometric redshift errors on the parameter constraints. We find that different statistics lead to different bias directions in parameter space, suggesting the possibility of eliminating this bias via self-calibration.}, author = {Petri, Andrea and May, Morgan and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, title = {{Cosmology with photometric weak lensing surveys: Constraints with redshift tomography of convergence peaks and moments}}, doi = {10.1103/physrevd.94.063534}, volume = {94}, year = {2016}, } @article{17628, abstract = {Constraining cosmology using weak gravitational lensing consists of comparing a measured feature vector of dimension 𝑁𝑏 with its simulated counterpart. An accurate estimate of the 𝑁𝑏×𝑁𝑏 feature covariance matrix 𝐂 is essential to obtain accurate parameter confidence intervals. When 𝐂 is measured from a set of simulations, an important question is how large this set should be. To answer this question, we construct different ensembles of 𝑁𝑟 realizations of the shear field, using a common randomization procedure that recycles the outputs from a smaller number 𝑁𝑠≤𝑁𝑟 of independent ray-tracing 𝑁-body simulations. We study parameter confidence intervals as a function of (𝑁𝑠, 𝑁𝑟) in the range 1≤𝑁𝑠≤200 and 1≤𝑁𝑟≲105. Previous work [S. Dodelson and M. D. Schneider, Phys. Rev. D 88, 063537 (2013)] has shown that Gaussian noise in the feature vectors (from which the covariance is estimated) lead, at quadratic order, to an 𝑂⁢(1/𝑁𝑟) degradation of the parameter confidence intervals. Using a variety of lensing features measured in our simulations, including shear-shear power spectra and peak counts, we show that cubic and quartic covariance fluctuations lead to additional 𝑂⁢(1/𝑁2𝑟) error degradation that is not negligible when 𝑁𝑟 is only a factor of few larger than 𝑁𝑏. We study the large 𝑁𝑟 limit, and find that a single, 240  Mpc/ℎ sized 5123-particle 𝑁-body simulation (𝑁𝑠=1) can be repeatedly recycled to produce as many as 𝑁𝑟=few×104 shear maps whose power spectra and high-significance peak counts can be treated as statistically independent. As a result, a small number of simulations (𝑁𝑠=1 or 2) is sufficient to forecast parameter confidence intervals at percent accuracy.}, author = {Petri, Andrea and Haiman, Zoltán and May, Morgan}, issn = {2470-0010}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, title = {{Sample variance in weak lensing: How many simulations are required?}}, doi = {10.1103/physrevd.93.063524}, volume = {93}, year = {2016}, } @article{17649, abstract = {Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on Ωm and σ8 are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational data from the 154 deg2 Canada-France-Hawaii Telescope Lensing Survey. We found that while high peaks (with height κ >3.5 σκ, where σκ is the r.m.s. of the convergence κ) are typically due to one single massive halo of ~1015M⊙, low peaks (κ <~ σκ) are associated with constellations of 2-8 smaller halos (<~1013M⊙). In addition, halos responsible for forming low peaks are found to be significantly offset from the line-of-sight towards the peak center (impact parameter >~ their virial radii), compared with ~0.25 virial radii for halos linked with high peaks, hinting that low peaks are more immune to baryonic processes whose impact is confined to the inner regions of the dark matter halos. Our findings are in good agreement with results from the simulation work by Yang el al. (2011).}, author = {Liu, Jia and Haiman, Zoltán}, issn = {2470-0010}, journal = {Physical Review D}, number = {4}, publisher = {American Physical Society}, title = {{Origin of weak lensing convergence peaks}}, doi = {10.1103/physrevd.94.043533}, volume = {94}, year = {2016}, }