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We examine the possibility of applying the baryonic acoustic oscillation reconstruction method to improve the neutrino mass Σm ν constraint. Thanks to the Gaussianization of the process, we demonstrate that the reconstruction algorithm could improve the measurement accuracy by roughly a factor of two. On the other hand, the reconstruction process itself becomes a source of systematic error. While the algorithm is supposed to produce the displacement field from a density distribution, various approximations cause the reconstructed output to deviate on intermediate scales. Nevertheless, it is still possible to benefit from this Gaussianized field, given that we can carefully calibrate the “transfer function” between the reconstruction output and theoretical displacement divergence from simulations. The limitation of this approach is then set by the numerical stability of this transfer function. With an ensemble of simulations, we show that such systematic error could become comparable to statistical uncertainties for a DESI-like survey and be safely neglected for other less ambitious surveys.

We consider the consequences of a matter power spectrum which rises on small scales until eventually being cutoff by microphysical processes associated with the particle nature of dark matter. Evolving the perturbations of a weakly interacting massive particle from before decoupling until deep in the nonlinear regime, we show that nonlinear structure can form abundantly at very high redshifts. In such a scenario, dark matter annihilation is substantially increased after matter-radiation equality. Furthermore, since the power spectrum can be increased over a broad range of scales, the first star forming halos may form earlier than usual as well. The next challenge is determining how early Universe observations may constrain such enhanced dark matter perturbations., Comment: 19 pages, 16 figures

Baryonic feedback can significantly modify the spatial distribution of matter on small scales and create a bulk relative velocity between the dominant cold dark matter and the hot gas. We study the consequences of such bulk motions using two high-resolution hydrodynamic simulations, one with no feedback and one with very strong feedback. We find that relative velocities of order $100\ {\rm km}\, {\rm s}^{-1}$ are produced in the strong feedback simulation, whereas it is much smaller when there is no feedback. Such relative motions induce dipole distortions to the gas, which we quantify by computing the dipole correlation function. We find halo coordinates and velocities are systematically changed in the direction of the relative velocity. Finally, we discuss potential to observe the relative velocity via large-scale structure, Sunyaev–Zel’dovich and line emission measurements. Given the non-linear nature of this effect, it should next be studied in simulations with different feedback implementations/strengths to determine the available model space.

We analytically model the non-linear effects induced by massive neutrinos on the total matter power spectrum using the halo model reaction framework of Cataneo et al. 2019. In this approach the halo model is used to determine the relative change to the matter power spectrum caused by new physics beyond the concordance cosmology. Using standard fitting functions for the halo abundance and the halo mass-concentration relation, the total matter power spectrum in the presence of massive neutrinos is predicted to percent-level accuracy, out to $k=10 \, h \, {\rm Mpc}^{-1}$. We find that refining the prescriptions for the halo properties using $N$-body simulations improves the recovered accuracy to better than 1%. This paper serves as another demonstration for how the halo model reaction framework, in combination with a single suite of standard $\Lambda$CDM simulations, can recover percent-level accurate predictions for beyond-$\Lambda$CDM matter power spectra, well into the non-linear regime., Comment: 7 pages, 3 figures; matches MNRAS accepted version

Even if massive ($10\,M_\odot \lesssim M \lesssim 10^4 M_\odot$) primordial black holes (PBHs) can only account for a small fraction of the dark matter (DM) in the universe, they may still be responsible for a sizable fraction of the coalescence events measured by LIGO/Virgo, and/or act as progenitors of the supermassive black holes (SMBHs) observed already at high redshift ($z\gtrsim 6$). In presence of a dominant, non-PBH DM component, the bounds set by CMB via an altered ionization history are modified. We revisit the cosmological accretion of a DM halo around PBHs via toy models and dedicated numerical simulations, deriving updated CMB bounds which also take into account the last Planck data release. We prove that these constraints dominate over other constraints available in the literature at masses $M\gtrsim 20-50\,M_\odot$ (depending on uncertainty in accretion physics), reaching the level $f_{\rm PBH}, 14 pages, 7 figures. v2: Minor clarifications added and extra references. Matches published version

Reconstruction techniques are commonly used in cosmology to reduce complicated nonlinear behaviours to a more tractable linearized system. We study a new reconstruction technique that uses the Moving-Mesh algorithm to estimate the displacement field from nonlinear matter distribution. We show the performance of this new technique by quantifying its ability to reconstruct linear modes. We study the cumulative Fisher information $I(

Cold dark matter (CDM) could be composed of primordial black holes (PBH) in addition to or instead of more orthodox weakly interacting massive particle dark matter (PDM). We study the formation of the first structures in such $\mathrm{\ensuremath{\Lambda}}\mathrm{PBH}$ cosmologies using $N$-body simulations evolved from deep in the radiation era to redshift 99. When PBH are only a small component of the CDM, they are clothed by PDM to form isolated halos. On the other hand, when PBH make most of the CDM, halos can also grow via clustering of many PBH. We find that the halo mass function is well modelled via Poisson statistics assuming random initial conditions. We quantify the nonlinear velocities induced by structure formation and find that they are too small to significantly impact CMB constraints. A chief challenge is how best to extrapolate our results to lower redshifts relevant for some observational constraints.

The cosmic neutrino background is an important component of the Universe that is difficult to include in cosmological simulations due to the extremely large velocity dispersion of neutrino particles. We develop a new approach to simulate cosmic neutrinos that decomposes the Fermi-Dirac phase space into shells of constant speed and then evolves those shells using hydrodynamic equations. These collisionless hydrodynamic equations are chosen to match linear theory, free particle evolution and allow for superposition. We implement this method into the information-optimized cosmological $N$-body code CUBE and demonstrate that neutrino perturbations can be accurately resolved to at least $k\sim1\ h/$Mpc. This technique allows for neutrino memory requirements to be decreased by up to $\sim 10^3$ compared to traditional $N$-body methods., Comment: 11 pages, 6 figures

In an effort to address the legacies of massive human rights abuses and to restore the harms that have been caused, access to justice in the Democratic Republic of the Congo should be seen within a broad context. Central to the fulfilment of such a broad understanding of access to justice is victim participation. The legal framework of the DRC permits a wide range of participatory rights for victims in criminal proceedings. However, until recently the authority to prosecute serious violations of international human rights law, namely, genocide, crimes against humanity and war crimes, were exclusively held by the DRC's military courts. With the adoption of legislation in 2016 amending the Congolese Criminal Code and the Code of Criminal Procedure, what remains unclear is how victim participation will be operationalised once domestic courts start prosecuting these international crimes. The purpose of this article is to respond to these concerns.

Prior to the adoption of the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP) many African states held a unified and seemingly hostile position towards the UNDRIP exemplified by the concerns outlined in the African Group's Draft Aide Memoire. In order to gain a better understanding of the protections offered to indigenous peoples on the African continent, it is necessary to examine the concerns raised in the aforementioned Draft Aide Memoire and highlight how these concerns have been addressed at the regional level, effectively changing how the human rights norms contained within the UNDRIP are seen, understood and interpreted in the African context. The purpose of this article is to do just that: to examine in particular how the issue of defining indigenous peoples has been tackled on the African continent, how the right to self-determination has unfolded for indigenous peoples in Africa and how indigenous peoples' right to free, prior and informed consent has been interpreted at the regional level.

Astrophysical techniques have pioneered the discovery of neutrino mass properties. Current cosmological observations give an upper bound on neutrino masses by attempting to disentangle the small neutrino contribution from the sum of all matter using precise theoretical models. We discover the differential neutrino condensation effect in our TianNu N-body simulation. Neutrino masses can be inferred using this effect by comparing galaxy properties in regions of the universe with different neutrino relative abundance (i.e. the local neutrino to cold dark matter density ratio). In "neutrino-rich"' regions, more neutrinos can be captured by massive halos compared to "neutrino-poor" regions. This effect differentially skews the halo mass function and opens up the path to independent neutrino mass measurements in current or future galaxy surveys., Comment: 15 pages, 6 figures

Measurements of neutrino mass in cosmological observations rely on two point statistics that are hindered by significant degeneracies with the optical depth and galaxy bias. The relative velocity effect between cold dark matter and neutrinos induces a large scale dipole into the matter density field and may be able to provide orthogonal constraints to standard techniques. We numerically investigate this dipole in the TianNu Simulation, which contains cold dark matter and 50 meV neutrinos. We first compute the dipole using a new linear response technique where we treat the displacement caused by the relative velocity as a phase in Fourier space and then integrate the matter power spectrum over redshift. Then, we compute the dipole numerically in real space using the simulation density and velocity fields. We find excellent agreement between the linear response and N-body methods. Utilizing the dipole as an observational tool will require two tracers of the matter distribution that are differently biased with respect to the neutrino density.

We present a description of cosmic neutrinos as a dispersive fluid. In this approach, the neutrino phase space is reduced to density and velocity fields alongside a scale-dependent sound speed. This sound speed depends on redshift, the initial neutrino phase space density and the cold dark matter gravitational potential. The latter is a new coupling between neutrinos and large scale structure not described by previous fluid approaches. We compute the sound speed in linear theory and find that it asymptotes to constants at small and large scales regardless of the gravitational potential. By comparing with neutrino N-body simulations, we measure the small scale sound speed and find it to be lower than linear theory predictions. This allows for an explanation of the discrepancy between N-body and linear response predictions for the neutrino power spectrum: neutrinos are still driven predominantly by the cold dark matter, but the sound speed on small scales is not stable to perturbations and decreases. Finally, we present a calibrated model for the neutrino power spectrum that requires no additional integrations outside of standard Boltzmann codes.

Constraining neutrino mass remains an elusive challenge in modern physics. Precision measurements are expected from several upcoming cosmological probes of large-scale structure. Achieving this goal relies on an equal level of precision from theoretical predictions of neutrino clustering. Numerical simulations of the non-linear evolution of cold dark matter and neutrinos play a pivotal role in this process. We incorporate neutrinos into the cosmological N-body code CUBEP3M and discuss the challenges associated with pushing to the extreme scales demanded by the neutrino problem. We highlight code optimizations made to exploit modern high performance computing architectures and present a novel method of data compression that reduces the phase-space particle footprint from 24 bytes in single precision to roughly 9 bytes. We scale the neutrino problem to the Tianhe-2 supercomputer and provide details of our production run, named TianNu, which uses 86% of the machine (13,824 compute nodes). With a total of 2.97 trillion particles, TianNu is currently the world's largest cosmological N-body simulation and improves upon previous neutrino simulations by two orders of magnitude in scale. We finish with a discussion of the unanticipated computational challenges that were encountered during the TianNu runtime., Comment: Accepted for publication in Research in Astronomy and Astrophysics

Despite a noticeable shift in recent years, indigenous peoples in Asia continue to experience many forms of human rights violations, with the most serious perhaps being the loss of traditional lands and territories. The purpose of this paper is to examine indigenous peoples’ land rights and its application in Southeast Asia. To that end, the paper will provide an overview of the development of indigenous peoples’ land rights internationally; offer regional perspectives from the Inter-American Court of Human Rights and the African Commission for Human and Peoples’ Rights; analyze the concept of indigenous peoples in Asia, juxtaposing it with concurrent difficulties being experienced on the African continent; examine three countries (Cambodia, the Philippines, and Malaysia) that recognize indigenous peoples’ land rights to some extent, whether through constitutional amendments, legislative reform, or domestic jurisprudence; and highlight the implementation gap between the rights of indigenous peoples in law and practice.

Discovering the mass of neutrinos is a principle goal in high energy physics and cosmology. In addition to cosmological measurements based on two-point statistics, the neutrino mass can also be estimated by observations of neutrino wakes resulting from the relative motion between dark matter and neutrinos. Such a detection relies on an accurate reconstruction of the dark matter-neutrino relative velocity which is affected by non-linear structure growth and galaxy bias. We investigate our ability to reconstruct this relative velocity using large N-body simulations where we evolve neutrinos as distinct particles alongside the dark matter. We find that the dark matter velocity power spectrum is overpredicted by linear theory whereas the neutrino velocity power spectrum is underpredicted. The magnitude of the relative velocity observed in the simulations is found to be lower than what is predicted in linear theory. Since neither the dark matter nor the neutrino velocity fields are directly observable from galaxy or 21 cm surveys, we test the accuracy of a reconstruction algorithm based on halo density fields and linear theory. Assuming prior knowledge of the halo bias, we find that the reconstructed relative velocities are highly correlated with the simulated ones with correlation coefficients of 0.94, 0.93, 0.91 and 0.88 for neutrinos of mass 0.05, 0.1, 0.2 and 0.4 eV. We confirm that the relative velocity field reconstructed from large scale structure observations such as galaxy or 21 cm surveys can be accurate in direction and, with appropriate scaling, magnitude., 10 pages, 11 figures

The relic neutrinos are expected to acquire a bulk relative velocity with respect to the dark matter at low redshifts, and neutrino wakes are expected to develop downstream of the dark matter halos. We propose a method of measuring the neutrino mass based on this mechanism. This neutrino wake will cause a dipole distortion of the galaxy-galaxy lensing pattern. This effect could be detected by combining upcoming lensing surveys with a low redshift galaxy survey or a 21 cm intensity mapping survey, which can map the neutrino flow field. The data obtained with LSST and Euclid should enable us to make a positive detection if the three neutrino masses are quasidegenerate with each neutrino mass of $\sim$0.1 eV, and a future high precision 21 cm lensing survey would allow the normal hierarchy and inverted hierarchy cases to be distinguished, and even the right-handed Dirac neutrinos may be detectable., 5 pages, 4 figures, v2 matches the published version

Beginning in the 20th century, international law expanded beyond law between nations to eventually embrace the concept of human rights. However, until recently, human rights efforts were focused mostly on individuals, their rights and the obligations of the state in question. Indigenous peoples, on the other hand, have always articulated their collective rights and, to their credit, achieved notable success. While there is no doubt that these achievements should be applauded, what is also of interest, and deserves further study, are the ways in which human rights jurisprudence concerning Indigenous peoples’ collective rights intermingle, cross-fertilize, and integrate. This dynamic relationship between the various sources of Indigenous rights law has had a tremendous impact locally, changing how states interact with the Indigenous peoples living within its borders. The first aim of this article will be to explore the above-mentioned topics in detail with a particular eye on the African human rights systems. Secondly, it will examine how they relate to the Endorois case that was recently decided by the African Commission on Human and Peoples’ Rights. I conclude with an investigation into what this could mean for Indigenous peoples’ rights in the African context.

We present a new technique to measure neutrino masses using their flow field relative to dark matter. Present day streaming motions of neutrinos relative to dark matter and baryons are several hundred km/s, comparable with their thermal velocity dispersion. This results in a unique dipole anisotropic distortion of the matter-neutrino cross power spectrum, which is observable through the dipole distortion in the cross correlation of different galaxy populations. Such a dipole vanishes if not for this relative velocity and so it is a clean signature for neutrino mass. We estimate the size of this effect and find that current and future galaxy surveys may be sensitive to these signature distortions., 5 pages, 4 figures, 1 table, version2 with supplemental materials, v3 matches the published version

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While many commentators have critiqued the lack of enforcement and monitoring mechanisms with the African human rights system, there have only been a few contributions that focus their analysis on the implementation of the recommendations provided by the African Commission on Human and Peoples’ Rights. This lacuna means that little is actually known of the status of state compliance. The purpose of this article is to address the issues of implementation and compliance by examining in detail the ‘aftermath’ of two decisions of the African Commission: Centre for Minority Rights Development (Kenya) and Minority Rights Group (on behalf of Endorois Welfare Council) v Kenya (Endorois) and Mr Mamboleo M Itundamilamba v Democratic Republic of Congo (Mamboleo). By analysing the way state parties have reacted to these findings, the article aims to shed some light on the effectiveness of the mechanisms set up to monitor compliance, highlights the arguments used by state parties when refusing to implement the recommendations of the African Commission and examines the ways in which implementation is avoided.

Victim participation has become a prominent feature in international criminal proceedings but it remains unclear how it will manifest itself once international crimes, notably war crimes, crimes against humanity and genocide, are adjudicated at the national level. The purpose of this Chapter is to respond to these concerns by examining developments in the Democratic Republic of Congo (DRC), compared and contrasted with developments at the international, hopefully allowing any gaps in the protection of victims’ participatory rights to surface. The Chapter will begin by highlighting the importance, and obligation, of States to use prosecutions as a post-conflict or transitional justice mechanism. This will be followed by providing an overview of the development of international legal standards with regards to victim participation, examining in particular the contributions of the International Criminal Court. The Chapter will conclude with presenting the DRC as a case study, including analysing the domestic legal framework, where victim participation exists in theory as a partie civile (civil party); analysing the jurisprudence arising from the military tribunals, as these courts have exclusive jurisdiction over crimes under international law, which points to a more restrained access for victims compared to criminal courts in the ordinary judicial system; and, examining recent developments, such as the proposed mixed tribunals and the implementation of international criminal law in national legislation.

Academic commentary highlighting the violations of human rights and international humanitarian law in the Democratic Republic of Congo and urging for change in national priorities in order to stop impunity and injustice in the country.