A pebbling move on a graph removes two pebbles at a vertex and adds one pebble at an adjacent vertex. Rubbling is a version of pebbling where an additional move is allowed. In this new move, one pebble each is removed at vertices v and w adjacent to a vertex u, and an extra pebble is added at vertex u. A vertex is reachable from a pebble distribution if it is possible to move a pebble to that v...

Ladders of recollements abelian categories are introduced, and used to address three general problems. a certain height allow construct triangulated categories, involving derived singularity from ones. also tilt recollements, ladders guarantee that properties like Gorenstein projective or injective preserved by some functors in recollements. Breaking symmetry is crucial developing this theory.

The formation of stripes in six-leg Hubbard ladders with cylindrical boundary conditions is investigated for two different hole dopings, where the amplitude of the hole density modulation is determined in the limits of vanishing DMRG truncation errors and infinitely long ladders. The results give strong evidence that stripes exist in the ground state of these systems for strong but not for weak...

marine polyether ladders (Figure 1 and Figure 2) can be grouped into 14 backbone structures and has gained much notoriety in being responsible for countless cases of human food poisoning and massive fish kills. Maitotoxin itself displays the highest toxicity of any nonproteinaceous natural product isolated thus far. The biogenesis of the polyether ladders, whilst attracting speculation, has adv...

We investigate weakly coupled spin-1/2 ladders in a magnetic field. The work is motivated by recent experiments on the compound (5CH12N2)CuBr4 (BPCB). We use a combination of numerical and analytical methods, in particular, the density-matrix renormalization group (DMRG) technique, to explore the phase diagram and the excitation spectra of such a system. We give detailed results on the temperat...

Understanding the physical properties of the chain-ladder Sr3Ca11Cu24O41 hole-doped superconductor has been precluded by the unknown hole distribution among chains and ladders. We use electron energy-loss spectrometry (EELS) in a scanning transmission electron microscope (STEM) at atomic resolution to directly separate the contributions of chains and ladders and to unravel the hole distribution...

The title one-dimensional coordination network, {[Gd(2)(NO(3))(6)(C(10)H(8)N(2)O(2))(3)]·2CH(2)Cl(2)}(n), is isostructural with the previously reported Tb and Tl coordination networks and to its Eu analog. The Gd(III) cation is coordinated in a distorted tricapped trigonal-prismatic fashion by nine O atoms from three bridging 4,4'-bipyridine N,N'-dioxide ligands and three chelating nitrate anio...

Sr Cu O ladder compounds contain linear frag ments of copper oxide planes In contrast to the two dimensional antiferromagnetic cuprates the spin two leg ladders have short range magnetic order and a spin gap Holes doped into these ladders pair and superconduct at high doping concentrations while insulators are known to result from low hole concen trations The competition between insulating stat...

Hubbard ladders are an important stepping stone to the physics of the two-dimensional Hubbard model. While many of their properties are accessible to numerical and analytical techniques, the question of whether weakly hole-doped Hubbard ladders are dominated by superconducting or charge-density-wave correlations has so far eluded a definitive answer. In particular, previous numerical simulation...