Numerical results for the exact spectrum of planar AdS4/CFT3

We compute the anomalous dimension for a short single-trace operator in planar ABJM theory at intermediate coupling. This is done by solving numerically the set of Thermodynamic Bethe Ansatz equations which are expected to describe the exact spectrum of the theory. We implement a truncation method which significantly reduces the number of integral equations to be solved and improves numerical efficiency. Results are obtained for a range of 't Hooft coupling lambda corresponding to $0 \leq h(\lambda) \leq 1$, where h(lambda) is the interpolating function of the AdS4/CFT3 Bethe equations.Comment: v3: corrected Acknowledgements section; v4: minor changes, published version; v5: fixed typos in Eq. (3.9

Spin Caloritronics

This is a brief overview of the state of the art of spin caloritronics, the science and technology of controlling heat currents by the electron spin degree of freedom (and vice versa).Comment: To be published in "Spin Current", edited by S. Maekawa, E. Saitoh, S. Valenzuela and Y. Kimura, Oxford University Pres

On wrapping corrections to GKP-like operators

In the recent paper arXiv:1010.5009, Maldacena et al. derive the two loop expressions for polygonal Wilson loops expectation values, or MHV amplitudes, by writing them as sums over exchanges of intermediate free particles. The spectrum of excitations of the flux tube between two null Wilson lines can be viewed as the spectrum of excitations around the infinite spin limit of finite twist operators in the sl(2) sector of N=4 SYM or the Gubser-Klebanov-Polyakov (GKP) string. This regime can be captured exploiting integrability and assuming that wrapping corrections are negligible compared to asymptotic Bethe Ansatz contributions. This assumption holds true for the N=4 SYM background GKP string, but deserves further analysis for excited states. Here, we investigate GKP cousins by considering various classes of (generalized) twist operators in beta-deformed N=4 SYM and ABJM theory. We show that the Y-system of Gromov-Kazakov-Vieira easily leads to accurate large spin expansions of the wrapping correction at lowest order in weak-coupling perturbation theory. As a byproduct, we confirm that wrapping corrections are subleading in all the considered cases.Comment: 37 pages, 6 eps figure

Spontaneous reduction and C-H borylation of arenes mediated by uranium(III) disproportionation

Transition-metal-arene complexes such as bis(benzene)chromium Cr(eta(6)-C6H6)(2) are historically important to d-orbital bonding theory and have modern importance in organic synthesis, catalysis and organic spintronics. In investigations of f-block chemistry, however, arenes are invariably used as solvents rather than ligands. Here, we show that simple uranium complexes UX3 (X = aryloxide, amide) spontaneously disproportionate, transferring an electron and X-ligand, allowing the resulting UX2 to bind and reduce arenes, forming inverse sandwich molecules [X2U(mu-eta(6):eta(6)-arene)UX2] and a UX4 by-product. Calculations and kinetic studies suggest a 'cooperative small-molecule activation' mechanism involving spontaneous arene reduction as an X-ligand is transferred. These mild reaction conditions allow functionalized arenes such as arylsilanes to be incorporated. The bulky UX3 are also inert to reagents such as boranes that would react with the traditional harsh reaction conditions, allowing the development of a new in situ arene C-H bond functionalization methodology converting C-H to C-B bonds.</p