We describe our recent attempts to model substructure in dark matter halos down to very small masses, using a semi-analytic model of halo formation. The results suggest that numerical simulations of halo formation may still be missing substructure in the central regions of halos due to purely numerical effects. If confirmed, this central 'overmerging' problem will have important consequences fo...

A procedure for line-shape analysis of broadened X-ray (or neutron) diffraction peaks is presented and specified for b.c.c. materials, which takes into account the effect of interfaces, internal stress of the 2nd kind and a dislocation distribution with weak defect correlation. Application of the technique is demonstrated by the estimation of dislocation densities in plastically deformed a-iron...

The Higgs mechanism is the favourite cure for the main problem with electroweak unification, namely how to reconcile a gauge theory with the need for massive gauge bosons. This problem does not exist in preon models for quark and lepton substructure with composite Z 0 and W s, which, consequently, also avoid all other theoretical complications and paradoxes with the Higgs mechanism. We present ...

This paper is the rst in a series of three which culminates in an ordinal analysis of 1 2-comprehension. On the set-theoretic side 1 2-comprehension corresponds to Kripke-Platek set theory, KP, plus 1-separation. The strength of the latter theory is encapsulated in the fact that it proves the existence of ordinals such that, for all > , is-stable, i.e. L is a 1-elementary substructure of L. The...

Observations of multiple-image gravitational lens systems suggest that the projected mass distributions of galaxy haloes may contain substantial inhomogeneities. The fraction of the halo mass in dense substructure is still highly uncertain, but could be as large as a few percent. While halo substructure is seen in numerical simulations of CDM haloes, little of this substructure survives in the ...

Annihilating dark matter (DM) has been discussed as a possible source of gamma rays from the galactic center and as a contribution to the extragalactic gamma-ray background. Assuming universality of the density profile of DM halos, we show that it is quite unlikely that DM annihilation is a main constituent of extragalactic gamma-ray background, without exceeding the observed gamma-ray flux fro...

Proof assistants aid the user in proving mathematical theorems by taking care of low-level reasoning details. Their user interfaces often present proof information as text, which becomes increasingly difficult to comprehend as it grows in size. Panoptes is a software tool that enables users to explore graphical representations of the formal proofs produced by the imps Interactive Mathematical P...

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The DSHARP survey evidenced the ubiquity of substructure in mm dust distribution large, bright protoplanetary discs. Intriguingly, these datasets have yet higher resolution information that is not recovered a CLEAN image. We first show intrinsic performance algorithm resolution-limited. Then analyzing all 20 sources using 1D, super-resolution code Frankenstein (frank), we accurately fit 1D visi...