nils-herrmann/clean_scirepeval huggingface dataset:
Unitarity Constraints on Asymmetric Freeze-In

This paper considers unitarity and CPT constraints on asymmetric freeze-in, the use of freeze-in to store baryon number in a dark sector. In this scenario, Sakharov's out of equilibrium condition is satisfied by placing the visible and hidden sectors at different temperatures while a net visible baryon number is produced by storing negative baryon number in a dark sector. It is shown that unitarity and CPT lead to unexpected cancellations. In particular, the transfer of baryon number cancels completely at leading order. This note has shown that if two sectors are in thermal equilibrium with themselves, but not with each other, then the leading effect transferring conserved quantities between the two sectors is of order the the weak coupling connecting them to the third power. When freeze-in is used to produce a net baryon number density, the leading order effect comes from {Omicron}({lambda}{sup 3}) diagrams where the intermediate state that goes on-shell has a different visible baryon number than the final state visible baryon number. Models in which the correct baryon number is generated with freeze-in as the dominant source of abundance, typically require {lambda} {approx}> 10{sup -6} and m{sub bath} {approx}> TeV. m{sub bath} is the mass of the visible particle which communicates with the hidden sector. The lower window is potentially observable at the LHC.
On the DAMA and CoGeNT Modulations

DAMA observes an annual modulation in their event rate, as might be expected from dark matter scatterings, while CoGeNT has reported evidence for a similar modulation. The simplest interpretation of these findings in terms of dark matter-nucleus scatterings is excluded by other direct detection experiments. We consider the robustness of these exclusions with respect to assumptions regarding the scattering and find that isospin-violating inelastic dark matter helps alleviate this tension and allows marginal compatibility between experiments. Isospin-violation can significantly weaken the XENON constraints, while inelasticity enhances the annual modulation fraction of the signal, bringing the CoGeNT and CDMS results into better agreement.
How to make graphene superconducting

Graphene  is the physical realization of many funda- mental concepts and phenomena in solid state-physics[2], but in the long list of graphene remarkable proper- ties [3-6], a fundamental block is missing: supercon- ductivity. Making graphene superconducting is relevant as the easy manipulation of this material by nanolyto- graphic techniques paves the way to nanosquids, one- electron superconductor-quantum dot devices[7, 8], su- perconducting transistors at the nano-scale[9] and cryo- genic solid-state coolers[10]. Here we explore the doping of graphene by adatoms coverage. We show that the occurrence of superconduc- tivity depends on the adatom in analogy with graphite intercalated compounds (GICs). However, most surpris- ingly, and contrary to the GIC case[11, 12], Li covered graphene is superconducting at much higher temperature with respect to Ca covered graphene. As graphene itself is not superconducting, phonon- mediated superconductivity must be induced by an en- hancement of the electron-phonon coupling ( ), = N(0)D2 M!2 ph (1) In Eq. 1 N(0) is the electronic density of states (DOS) at the Fermi level, D is the deformation potential, while M and !ph are effective atom mass and phonon frequency that in metallic alloys reflect the role of the different atomic species and phonon vibrations involved in su- perconductivity. In undoped graphene is small and phonon-mediated superconductivity does not occur as the small number of carriers, intrinsic in a semimetal, leads to a vanishingly small N(0). In this respect the sit- uation is similar to the bulk graphite case, where, with- out intercalation of foreign atoms superconductivity is not stabilized.
Exciton-spin memory with a semiconductor quantum dot molecule.

We report on a single photon and spin storage device based on a semiconductor quantum dot molecule. Optically excited single electron-hole pairs are trapped within the molecule, and their recombination rate is electrically controlled over 3 orders of magnitude. Single photons are stored up to 1 μs and read out on a subnanosecond time scale. By using resonant excitation, the circular polarization of individual photons is transferred into the spin state of electron-hole pairs with a fidelity above 80%, which does not degrade for storage times up to the 12.5 ns repetition period of the experiment.
Modulation of near-field heat transfer between two gratings

We present a theoretical study of near-field heat transfer between two uniaxial anisotropic planar structures. We investigate how the distance and relative orientation (with respect to their optical axes) between the objects affect the heat flux. In particular, we show that by changing the angle between the optical axes it is possible in certain cases to modulate the net heat flux up to 90% at room temperature, and discuss possible applications of such a strong effect.
Multiverse interpretation of quantum mechanics

We argue that the many-worlds of quantum mechanics and the many worlds of the multiverse are the same thing, and that the multiverse is necessary to give exact operational meaning to probabilistic predictions from quantum mechanics. 
Decoherence - the modern version of wave-function collapse - is subjective in that it depends on the choice of a set of unmonitored degrees of freedom, the "environment". In fact decoherence is absent in the complete description of any region larger than the future light-cone of a measurement event. However, if one restricts to the causal diamond - the largest region that can be causally probed - then the boundary of the diamond acts as a one-way membrane and thus provides a preferred choice of environment. We argue that the global multiverse is a representation of the many-worlds (all possible decoherent causal diamond histories) in a single geometry. 
We propose that it must be possible in principle to verify quantum-mechanical predictions exactly. This requires not only the existence of exact observables but two additional postulates: a single observer within the universe can access infinitely many identical experiments; and the outcome of each experiment must be completely definite. In causal diamonds with finite surface area, holographic entropy bounds imply that no exact observables exist, and both postulates fail: experiments cannot be repeated infinitely many times; and decoherence is not completely irreversible, so outcomes are not definite. We argue that our postulates can be satisfied in "hats" (supersymmetric multiverse regions with vanishing cosmological constant). We propose a complementarity principle that relates the approximate observables associated with finite causal diamonds to exact observables in the hat.
Charge Asymmetric Cosmic Ray Signals From Dark Matter Decay

The PAMELA and Fermi measurements of the cosmic-ray electron and positron spectra have generated much interest over the past two years, because they are consistent with a significant component of the electron and positron fluxes between 20 GeV and 1 TeV being produced through dark matter annihilation or decay. However, since the measurements are also consistent with astrophysical interpretations, the message is unclear. In this paper, we point out that dark matter can have a more distinct signal in cosmic rays, that of a charge asymmetry. Such charge asymmetry can result if the dark matter's abundance is due to a relic asymmetry, allowing its decay to generate an asymmetry in positrons and electrons. This is analogous to the baryon asymmetry, where decaying neutrons produce electrons and not positrons. We explore benchmark scenarios where the dark matter decays into a leptophilic charged Higgs boson or electroweak gauge bosons. These models have observable signals in gamma rays and neutrinos, which can be tested by Fermi and IceCube. The most powerful test will be at AMS-02, given its ability to distinguish electron and positron charge above 100 GeV. Specifically, an asymmetry favoring positrons typically predicts a larger positron ratio and a harder (softer) high energy spectrum for positrons (electrons) than charge symmetric sources. We end with a brief discussion on how such scenarios differ from the leading astrophysical explanations.
Operational dynamic modeling transcending quantum and classical mechanics.

We introduce a general and systematic theoretical framework for operational dynamic modeling (ODM) by combining a kinematic description of a model with the evolution of the dynamical average values. The kinematics includes the algebra of the observables and their defined averages. The evolution of the average values is drawn in the form of Ehrenfest-like theorems. We show that ODM is capable of encompassing wide-ranging dynamics from classical non-relativistic mechanics to quantum field theory. The generality of ODM should provide a basis for formulating novel theories.
Capability of the Free-Ion Eigenstates for Crystal-Field Splitting

Any electronic eigenstate of the paramagnetic ion open-shell is characterized by the three independent multipole asphericities for and 6 related to the second moments of the relevant crystal-field splittings by , where . The Ak as the reduced matrix elements can serve as a reliable measure of the state capability for the splitting produced by the k-rank component of the crystal-field Hamiltonian. These multipolar characteristics allow one to verify any fitted crystal-field parameter set by comparing the calculated second moments and the experimental ones of the relevant crystal-field splittings. We present the multipole characteristics Ak for the extensive set of eigenstates from the lower parts of energy spectra of the tripositive 4 f N ions applying in the calculations the improved eigenfunctions of the free lanthanide ions obtained based on the M. Reid f-shell programs. Such amended asphericities are compared with those achieved for the simplified Russell-Saunders states. Next, they are classified with respect to the absolute or relative weight of Ak in the multipole structure of the considered states. For the majority of the analyzed states (about 80%) the Ak variation is of order of only a few percent. Some essential changes are found primarily for several states of Tm3+, Er3+, Nd3+, and Pr3+ ions. The detailed mechanisms of such Ak changes are unveiled. Particularly, certain noteworthy cancelations as well as enhancements of their magnitudes are explained.
Is geometry bosonic or fermionic

It is generally assumed that the gravitational field is bosonic. Here we show that a simple propagating torsional theory can give rise to localized geometric structures that can consistently be quantized as fermions under exchange. To demonstrate this, we show that the model can be formally mapped onto the Skyrme model of baryons, and we use well-known results from Skyrme theory. This begs the question: {\it Is geometry bosonic or fermionic (or both)?}
Static hybrid potential in D dimensions at short distances

We compute the energy of a static hybrid, i.e., of a hybrid quarkonium with static quark and antiquark, at short distances in $D=4,3$, dimensions. The soft contribution to this energy is the static potential of a color-octet quark-antiquark pair at short distances, which is known at two loops for arbitrary $D$. We have checked this expression employing thermal field theory methods. Using the effective field theory potential nonrelativistic QCD we calculate the ultrasoft contributions to the hybrid (and singlet) static energy at the two-loop level. We then present new results for the static hybrid energy/potential and the hybrid decay width in three and four dimensions. Finally we comment on the meaning of the perturbative results in two space-time dimensions, where the hybrid does not exist.
THE GAS−GALAXY CONNECTION AT zabs = 0.35: O vi AND H i ABSORPTION TOWARD J 0943+0531

We present observations of H i and O vi absorption systems proximate to a galaxy at zgal = 0.3529. The absorption was detected serendipitously in Cosmic Origins Spectrograph observations of the low-z QSO J 0943 + 0531 (zqso = 0.564). The data show two separate clouds along the sightline at an impact parameter of 95 kpc from the galaxy. The first is likely low-metallicity gas falling onto the galaxy. This assessment is based on the high velocity offset of the cloud from the galaxy (Δv = 365 km s−1) and the weak metal line absorption, combined with photoionization modeling. The second cloud, with only a modest velocity separation from the galaxy (Δv = 85 km s−1), exhibits very strong O vi absorption qualitatively similar to O vi absorption seen in the Milky Way halo. Collisional ionization equilibrium models are ruled out by the metal line column density ratios. Photoionization modeling implies a length scale for the O vi cloud of ∼0.1–1.2 Mpc, which indicates the absorbing gas most likely resides within the local filamentary structure. This system emphasizes that kinematic association alone is not sufficient to establish a physical connection to galaxies, even at small impact parameters and velocity separations. Observations such as these, connecting galaxies with their gaseous environments, are becoming increasingly important for understanding of galaxy evolution and provide constraints for cosmological simulations.
Angular harmonics of the excitonic polarization conversion effect

We suggest a phenomenological theory of the polarization conversions effect, an excitonic analog of the first-order spatial dispersion phenomena which is, however, observed in the photoluminescence rather than in the passing light. The optical polarization response of a model system of electrically neutral quantum dots subject to the magnetic field along the growth axis was calculated by means of the pseudospin method. All possible forms of the polarization response are determined by nine different field-dependent coefficients which represent, therefore, a natural basis for classification of a variety of conversions. Existing experimental data can be well inscribed in this classification scheme. Predictions were made regarding two effects which have not been addressed experimentally.
Cosmological perturbation analysis in a scale invariant model of gravity

We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this model all the dimensionful parameters such as the gravitational constant and the cosmological constant etc are generated by a solution of the classical equations of motion. Hence, this solution provides a mechanism to break scale invariance. In this paper, we demonstrate the stability of such a solution against small perturbations in a flat FRW background by making a perturbative expansion around this solution and solving the resulting equations linear in the perturbations. This demonstrates the robustness of this symmetry breaking mechanism.
Hybrid Nanocavity Resonant Enhancement of Color Center Emission in Diamond

Resonantly enhanced emission from the zero-phonon line of a diamond nitrogen-vacancy (NV) center in single crystal diamond is demonstrated experimentally using a hybrid whispering gallery mode nanocavity. A 900 nm diameter ring nanocavity formed from gallium phosphide, whose sidewalls extend into a diamond substrate, is tuned onto resonance at a low temperature with the zero-phonon line of a negatively charged NV center implanted near the diamond surface. When the nanocavity is on resonance, the zero-phonon line intensity is enhanced by approximately an order of magnitude, and the spontaneous emission lifetime of the NV is reduced by as much as 18%, corresponding to a 6.3X enhancement of emission in the zero photon line.
Weyl semimetal in a topological insulator multilayer.

We propose a simple realization of the three-dimensional (3D) Weyl semimetal phase, utilizing a multilayer structure, composed of identical thin films of a magnetically doped 3D topological insulator, separated by ordinary-insulator spacer layers. We show that the phase diagram of this system contains a Weyl semimetal phase of the simplest possible kind, with only two Dirac nodes of opposite chirality, separated in momentum space, in its band structure. This Weyl semimetal has a finite anomalous Hall conductivity and chiral edge states and occurs as an intermediate phase between an ordinary insulator and a 3D quantum anomalous Hall insulator. We find that the Weyl semimetal has a nonzero dc conductivity at zero temperature, but Drude weight vanishing as T(2), and is thus an unusual metallic phase, characterized by a finite anomalous Hall conductivity and topologically protected edge states.
Are GRB 090423 and similar bursts due to superconducting cosmic strings?

Superconducting cosmic strings may be able to power energetic gamma-ray bursts, in particular at high-redshifts ($z>6$). The ultra-relativistic outflows driven by the superconducting cosmic strings, however, seem too narrow to be consistent with the afterglow data of GRB 090423 and GRB 080913.
Gravitational Radiation in Horava Gravity

We study the radiation of gravitational waves by self-gravitating binary systems in the low-energy limit of Horava gravity. We find that the predictions for the energy-loss formula of general relativity are modified already for Newtonian sources: the quadrupole contribution is altered, in part due to the different speed of propagation of the tensor modes; furthermore, there is a monopole contribution stemming from an extra scalar degree of freedom. A dipole contribution only appears at higher post-Newtonian order. We use these findings to constrain the low-energy action of Horava gravity by comparing them with the radiation damping observed for binary pulsars. Even if this comparison is not completely appropriate-since compact objects cannot be described within the post-Newtonian approximation-it represents an order of magnitude estimate. In the limit where the post-Newtonian metric coincides with that of general relativity, our energy-loss formula provides the strongest constraints for Horava gravity at low-energies.
Dynamic multiscaling in two-dimensional fluid turbulence.

We obtain, by extensive direct numerical simulations, time-dependent and equal-time structure functions for the vorticity, in both quasi-Lagrangian and Eulerian frames, for the direct-cascade regime in two-dimensional fluid turbulence with air-drag-induced friction. We show that different ways of extracting time scales from these time-dependent structure functions lead to different dynamic-multiscaling exponents, which are related to equal-time multiscaling exponents by different classes of bridge relations; for a representative value of the friction we verify that, given our error bars, these bridge relations hold.
Validation of Dunbar's number in Twitter conversations

Modern society’s increasing dependency on online tools for both work and recreation opens up unique opportunities for the study of social interactions. A large survey of online exchanges or conversations on Twitter, collected across six months involving 1.7 million individuals is presented here. We test the theoretical cognitive limit on the number of stable social relationships known as Dunbar’s number. We find that users can entertain a maximum of 100 − 200 stable relationships in support for Dunbar’s prediction. The “economy of attention” is limited in the online world by cognitive and biological constraints as predicted by Dunbar’s theory. Inspired by this empirical evidence we propose a simple dynamical mechanism, based on finite priority queuing and time resources, that reproduces the observed social behavior.
Some new insights on the statistical origin of the Bekenstein-Hawking entropy I: Some heuristic arguments

Now that the Bekenstein-Hawking entropy has been found within the traditional theory, its physical interpretation should hide in quantum field theory in curved spacetime (only its quantum corrections require a detailed knowledge of quantum gravity). However, to interpret the statistical origin of the Bekenstein-Hawking entropy, there have developed many microscopic pictures, some of them are based on the theories that themselves remain to be experimentally verified, while some cite the Hawking temperature formula and actually argue in circle (and then they have not provided more information than the seminal work of Bekenstein and Hawking). Within quantum field theory in curved spacetime (without introducing any new hypothesis), it is inevitable for us to attribute the Bekenstein-Hawking entropy to entanglement entropy. In the first part we just provide a heuristic argument, a rigorous theoretical model will be presented in our next work.
Non-Fermi liquid behavior of the drag and diffusion coefficients in QED plasma

We calculate the drag and diffusion coefficients in low temperature QED plasma and go beyond the leading order approximation. The non-Fermi-liquid behavior of these coefficients are clearly revealed. We observe that the subleading contributions due to the exchange of soft transverse photon in both cases are larger than the leading order terms coming from the longitudinal sector. The results are presented in closed form at zero and low temperature.
Testing Superstring Theories with Gravitational Waves

We provide a simple transfer function that determines the effect of an early matter dominated era on the gravitational wave background and show that a large class of compactifications of superstring theory might be tested by observations of the gravitational wave background from inflation. For large enough reheating temperatures $> 10^9 \GeV$ the test applies to all models containing at least one scalar with mass $< 10^{12}\GeV$ that acquires a large initial oscillation amplitude after inflation and has only gravitational interaction strength, i.e., a field with the typical properties of a modulus.
Strong-coupling effective action(s) for SU(3) Yang-Mills

We apply strong-coupling expansion techniques to finite-temperature lattice pure gauge theory, obtaining dimensionally reduced $Z_N$-symmetric effective theories. The analytic mappings between the effective couplings and the original one, viz. $\beta$, allow to estimate the transition point $\beta_c$ of the 4D theory for a large range of the imaginary-time extent $N_\tau$ of the lattice. We study the models for SU(3) via Monte Carlo simulation, finding satisfactory agreement with the critical point of the original theories especially at low $N_\tau$. We have fixed an error in the group measure used in  and provide here the correct numerical results.