TaO+^+, a Candidate Molecular Ion in Search of Physics Beyond the Standard Model

The TaO$^+$ molecular ion is proposed as a candidate system for detecting signatures of charge parity (${\cal{CP}}$) violating physics beyond the standard model of elementary particles. The electron electric dipole moment (EDM) effective electric field $E_{\text{eff}} = 20.2 \left[\frac{\rm GV}{\rm cm}\right]$, the nucleon-electron scalar-pseudoscalar (ne-SPS) interaction constant $W_{S} = 17.7$ [kHz] and the nuclear magnetic quadrupole interaction constant $W_M = 0.45$ [$\frac{10^{33} {\text{Hz}}}{e\, {\text{cm}}^2}$] are found to be sizeable ${\cal{P,T}}$-odd enhancements. The ratio of the leptonic and semi-leptonic enhancements differs strongly from the one for the ThO system which may provide improved limits on the electron EDM, $d_e$, and the SPS coupling constant, $C_S$. TaO$^+$ is found to have a ${^3\Delta_1}$ electronic ground state like the previously proposed ThF$^+$ molecular ion, but an order of magnitude smaller parallel G-tensor component which makes it less vulnerable to systematic errors in experiment.Comment: 9 pages, 1 figur

BKL oscillations in 2+1 space-time dimensions

We investigate the question whether there are cosmological models in 2+1 space-time dimensions which exhibit dynamics similar to BKL oscillations, as the cosmological singularity is approached. Based on intuition, we conceive a toy model which displays such oscillatory dynamics. We show that in the phase space of this model, the cosmological singularity is represented by a separatrix curve and discuss the model's dynamics within the cosmological billiards picture. Finally, we offer a physical interpretation for a family of similar cosmological models in terms of the topological degrees of freedom of gravity in 2+1 dimensions.Comment: 22 pages, 4 figure

Fourier expansions of Kac-Moody Eisenstein series and degenerate Whittaker vectors

Motivated by string theory scattering amplitudes that are invariant under a discrete U-duality, we study Fourier coefficients of Eisenstein series on Kac-Moody groups. In particular, we analyse the Eisenstein series on $E_9(R)$, $E_{10}(R)$ and $E_{11}(R)$ corresponding to certain degenerate principal series at the values s=3/2 and s=5/2 that were studied in 1204.3043. We show that these Eisenstein series have very simple Fourier coefficients as expected for their role as supersymmetric contributions to the higher derivative couplings $R^4$ and $\partial^{4} R^4$ coming from 1/2-BPS and 1/4-BPS instantons, respectively. This suggests that there exist minimal and next-to-minimal unipotent automorphic representations of the associated Kac-Moody groups to which these special Eisenstein series are attached. We also provide complete explicit expressions for degenerate Whittaker vectors of minimal Eisenstein series on $E_6(R)$, $E_7(R)$ and $E_8(R)$ that have not appeared in the literature before.Comment: 62 pages. Journal versio

The EOS data and information system

An overview of the approximate instrument data requirements is presented in tabular form. The function of data compression is briefly explained