In crowdfunding we trust : a trust-building model in lending crowdfunding

Trust critically affects the perceived probability of receiving expected returns on investment. Crowdfunding differs in many ways from traditional forms of investing. We have to ask what builds trust in this particular context. Based on literature regarding the formation of initial trust, we developed a model to explain which factors lead to crowdfunders’ trust in a crowdfunding project. We tested it on data collected from actual investors in a real project on a crowdlending platform. Our results show that trust in the crowdfunding platform and the information quality are more important factors of project trust than trust in the creator

Monolayer- and crystal-type MoO3 catalysts: Their catalytic properties in relation to their surface structures

Various MoO3 catalysts have been prepared by means of adsorption of molybdenum on supports from molybdate solutions or from the gas phase. Complete monomolecular layers of Mo6+ oxide can be prepared on the carriers Al2O3, Cr2O3, TiO2, CeO2, and ZrO2, whereas on SiO2 crystallites of MoO3 are formed. Reduction experiments show that the higher valencies of Mo are stabilized in the case of a monomolecular layer. Alcohol dehydration, pentene hydrogenation, and poisoning of these reactions with pyridine reveal that MoO2 present as a monolayer is less acidic than crystalline MoO2. On the complete monolayer catalysts investigated, mostly more than 70% of the dehydration and hydrogenation activities can be correlated with sites showing a relatively high acidity which are equivalent to 10–20% of the Mo content. The CO oxidation rates on the oxidized catalysts are antiparallel to those of the reactions on the reduced ones mentioned above; relatively basic sites preferentially chemisorb CO. The conclusion is that the activity pattern of the catalysts is a function of the acidity of the supports. It is suggested that Mo5+ ions contribute to the formation of the active acid sites after reduction with hydrogen

No Generalized TMD-Factorization in the Hadro-Production of High Transverse Momentum Hadrons

It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to simply modify the Wilson lines in the parton correlation functions for each separate hadron. In this paper, we will illustrate by direct counter-example that this is not possible in a non-Abelian gauge theory. Since a proof of generalized transverse momentum dependent factorization should apply generally to any hard hadro-production process, a single counter-example suffices to show that a general proof does not exist. Therefore, to make the counter-argument clear and explicit, we illustrate with a specific calculation for a double spin asymmetry in a spectator model with a non-Abelian gauge field. The observed breakdown of generalized transverse momentum dependent factorization challenges the notion that the role of parton transverse momentum in such processes can be described using separate correlation functions for each external hadron.Comment: 19 pages, 11 figures, typos fixed and minor explanations added, version to appear in Physical Review

Which Globular Clusters contain Intermediate-mass Black Holes?

It has been assumed that intermediate-mass black holes (IMBHs) in globular clusters can only reside in the most centrally concentrated clusters, with a so-called `core-collapsed' density profile. While this would be a natural guess, it is in fact wrong. We have followed the evolution of star clusters containing IMBHs with masses between 125 \le M_{BH} \le 1000 M_{\odot} through detailed N-body simulations, and we find that a cluster with an IMBH, in projection, appears to have a relatively large `core' with surface brightness only slightly rising toward the center. This makes it highly unlikely that any of `core-collapsed' clusters will harbor an IMBH. On the contrary, the places to look for an IMBH are those clusters that can be fitted well by medium-concentration King models. The velocity dispersion of the visible stars in a globular cluster with an IMBH is nearly constant well inside the apparent core radius. For a cluster of mass M_C containing an IMBH of mass M_{BH}, the influence of the IMBH becomes significant only at a fraction 2.5 M_{BH}/M_C of the half-mass radius, deep within the core, where it will affect only a small number of stars. In conclusion, observational detection of an IMBH may be possible, but will be challenging.Comment: 13 pages, 3 figures, Accepted ofr publication in ApJ (scheduled for February 2005

Reexamining the relation between debt mix and growth in Japan.

We propose a U-shaped relation between the relative weight of bank loans in total corporate debt and the firm's market-to-book ratio-a proxy for expected growth-which reconciles most existing theories. Using data on Japanese firms for 1983-97, we do find that, in the lower range of growth spectrum, firms with better prospects take more bonds in their debt mix: when the firm's prospects improve, the benefits from private debt initially fall relative to its costs. In contrast, in the higher range of growth, firms with more growth potentials take more monitored debt, reflecting, amongst other factors, the higher information and contracting costs of public debt faced by extreme growers. We can explain the seemingly conflicting evidence that Anderson and Makhija (1999) and Hoshi, Kashyap and Scharfstein (1993) provide in this respect. We also find that keiretsu firms do not behave significantly different from non-keiretsu ones, suggesting that keiretsu firms are fairly independent in their financing decisions and that extra costs and benefits from bank loans are either small or in reasonable balance. Firms that faced restrictions in issuing bonds, pre-1990, continue to behave differently from other firms long after the restrictions were lifted.

Positivity bounds on gluon TMDs for hadrons of spin ≤\le 1

We consider the transverse momentum dependent gluon distribution functions (called gluon TMDs) by studying the light-front gluon-gluon correlator, extending the results for unpolarized and vector polarized targets to also include tensor polarized targets -- the latter type of polarization is relevant for targets of spin $\ge1$. The light-front correlator includes process-dependent gauge links to guarantee color gauge invariance. As from the experimental side the gluon TMDs are largely unknown, we present positivity bounds for combinations of leading-twist gluon distributions that may be used to estimate their maximal contribution to observables. Since the gluonic content of hadrons is particularly relevant in the small-$x$ kinematic region, we also study these bounds in the small-$x$ limit for the dipole-type gauge link structure using matrix elements of a single Wilson loop.Comment: 10 page

Quantum Critical Exponents for a Disordered Three-Dimensional Weyl Node

Three-dimensional Dirac and Weyl semimetals exhibit a disorder-induced quantum phase transition between a semimetallic phase at weak disorder and a diffusive-metallic phase at strong disorder. Despite considerable effort, both numerically and analytically, the critical exponents $\nu$ and $z$ of this phase transition are not known precisely. Here we report a numerical calculation of the critical exponent $\nu=1.47\pm0.03$ using a minimal single-Weyl node model and a finite-size scaling analysis of conductance. Our high-precision numerical value for $\nu$ is incompatible with previous numerical studies on tight-binding models and with one- and two-loop calculations in an $\epsilon$-expansion scheme. We further obtain $z=1.49\pm0.02$ from the scaling of the conductivity with chemical potential