Strongly scale-dependent polyspectra from curvaton self-interactions
We study the scale dependence of the non-linearity parameters fNL and gNL in curvaton models with self-interactions. We show that the spectral indices nfNL = d ln|fNL|/d ln k and ngNL = d ln|gNL|/d ln k can take values much greater than the slow-roll parameters and the spectral index of the power spectrum. This means that the scale-dependence of the bi and trispectrum could be easily observable in this scenario with Planck, which would lead to tight additional constraints on the model. Inspite of the highly non-trivial behaviour of fNL and gNL in the curvaton models with self-interactions, we find that the model can be falsified if gNL(k) is also observed.

title: Constraining SuperWIMPy and Warm Subhalos with Future Submillilensing
abstract: We propose to observe QSO-galaxy strong lens systems to give a new constraint on the damping scale of the initial fluctuations. We find that the future observation of submilliarc scale astrometric shifts of the multiple lensed images of QSOs would find ∼ 10 ( 3 – 9 ) M ⊙ subhalos inside the macrolens halo. The superweakly interacting massive particles (superWIMPs) produced from a WIMP decay and the warm dark matter (WDM) particles that predict a comoving damping scale larger than ∼ 2 kpc can be constrained if ∼ 10 3 M ⊙ subhalos are detected.

title: Neutrino mass from cosmology: impact of high-accuracy measurement of the Hubble constant
abstract: Non-zero neutrino mass would affect the evolution of the Universe in observable ways, and a strong constraint on the mass can be achieved using combinations of cosmological data sets. We focus on the power spectrum of cosmic microwave background (CMB) anisotropies, the Hubble constant H0, and the length scale for baryon acoustic oscillations (BAO) to investigate the constraint on the neutrino mass, mν. We analyze data from multiple existing CMB studies (WMAP5, ACBAR, CBI, BOOMERANG, and QUAD), recent measurement of H0 (SHOES), with about two times lower uncertainty (5 %) than previous estimates, and recent treatments of BAO from the Sloan Digital Sky Survey (SDSS). We obtained an upper limit of mν < 0.2eV (95 % C.L.), for a flat ΛCDM model. This is a 40 % reduction in the limit derived from previous H0 estimates and one-third lower than can be achieved with extant CMB and BAO data. We also analyze the impact of smaller uncertainty on measurements of H0 as may be anticipated in the near term, in combination with CMB data from the Planck mission, and BAO data from the SDSS/BOSS program. We demonstrate the possibility of a 5σ detection for a fiducial neutrino mass of 0.1 eV or a 95 % upper limit of 0.04 eV for a fiducial of mν = 0 eV. These constraints are about 50 % better than those achieved without external constraint. We further investigate the impact on modeling where the dark-energy equation of state is constant but not necessarily -1, or where a non-flat universe is allowed. In these cases, the next-generation accuracies of Planck, BOSS, and 1 % measurement of H0 would all be required to obtain the limit mν < 0.05−0.06 eV (95 % C.L.) for the fiducial of mν = 0 eV. The independence of systematics argues for pursuit of both BAO and H0 measurements.

title: Correlated Isocurvature Fluctuation of Quintessence and Curvaton Scenario
abstract: We consider cosmic microwave background (CMB) anisotropy in models with quintessence taking into account of isocurvature fluctuation in the quintessence. It is shown that, if the primordial fluctuation of the quintessence has a correlation with the adiabatic density fluctuations, CMB angular power spectrum $C_l$ at low multipoles can be suppressed. Possible scenario of generating correlated mixture of the quintessence and adiabatic fluctuations is also discussed.

title: Bigger Rip with no dark energy
abstract: By studying a modified Friedmann equation which arises in an extension of general relativity which accommodates a time-dependent fundamental length L ( t ), we consider cosmological models where the scale factor diverges with an essential singularity at a finite future time. Such models have no dark energy in the conventional sense of energy possessing a simple pressure–energy relationship. Data on supernovae restrict the time from the present until the Rip to be longer than the current age of the Universe.

title: On the determination of neutrino masses and dark energy evolution from the cross-correlation of CMB and LSS
abstract: We discuss the possibilities of the simultaneous determination of the neutrino masses and the evolution of dark energy from future cosmological observations such as cosmic microwave background (CMB), large scale structure (LSS) and the cross-correlation between them. Recently it has been discussed that there is a degeneracy between the neutrino masses and the equation of state for dark energy. It is also known that there are some degeneracies among the parameters describing the dark energy evolution. We discuss the implications of these for the cross-correlation of CMB with LSS in some detail. Then we consider to what extent we can determine the neutrino masses and the dark energy evolution using the expected data from CMB, LSS and their cross-correlation.

title: Discovery of recombining plasma in the supernova remnant 3C 391
abstract: Recent X-ray study of middle-aged supernova remnants (SNRs) reveals strong radiative recombination continua (RRCs) associated with overionized plasmas, of which the origin still remains uncertain. We report our discovery of an RRC in the middle-aged SNR 3C 391. If the X-ray spectrum is fitted with a two-temperature plasma model in collisional ionization equilibrium (CIE), residuals of Si XIV Ly alpha line at 2.006 keV, S XVI Ly alpha line at 2.623 keV and the edge of RRC of Si XIII at 2.666 keV are found. The X-ray spectrum is better described by a composite model consisting of a CIE plasma and a recombining plasma (RP). The abundance pattern suggests that the RP is associated to the ejecta from a core-collapse supernova with a progenitor star of 15 solar mass. There is no significant difference of the recombining plasma parameters between the southeast region and the northwest region surrounded by dense molecular clouds. We also find a hint of Fe I K alpha line at 6.4 keV (~2.4 sigma detection) from the southeast region of the SNR.

title: Open string field theory on noncommutative space
abstract: We study Witten's open string field theory in the presence of a constant B field. We construct the string field theory in the operator formalism and find that, compared to the ordinary theory with no B field, the vertices in the resulting theory has an additional factor. The factor makes the zero modes of strings noncommutative. This is in agreement with the results in the first-quantized formulation. We also discuss background independence of the purely cubic action derived from the above string field theory and then find a redefinition of string fields to remove the additional factor from the vertex. Furthermore, we briefly discuss the supersymmetric extension of our string field theory.

title: ONE-LOOP TACHYON AMPLITUDE IN UNORIENTED OPEN-CLOSED STRING FIELD THEORY
abstract: We calculate one-loop 2-point tachyon amplitudes in unoriented open-closed string field theory, and determine all the coupling constants of the interaction vertices in the theory. It is shown that the planar, nonplanar and nonorientable amplitudes are all reproduced correctly, and nontrivial consistencies among the determined coupling constants are observed. The necessity for the gauge group to be SO(2 13 = 8192)is also reconfirmed. field theory (SFT)for an unoriented open-closed string mixed system and proved the BRS/gauge invariance of the action at the ‘tree level’; namely, we have classified the terms in the BRS transform of the action into two categories, ‘tree terms’ and ‘loop terms’, and have shown that all the tree terms indeed cancel among themselves. For the loop terms, we have identified which anomalous one-loop diagrams they are expected to cancel. It was left for a future work to show that the loop diagrams are indeed anomalous and that the loop terms actually cancel them. However, the task to show this BRS invariance for general one-loop diagrams is technically rather difficult, and we have not yet completed it. In this paper, we address an easier problem: to compute the one-loop 2-point (open-string)tachyon amplitudes in our SFT. These one-loop amplitudes already suffer from a BRS anomaly, and so the present calculation gives partially an affirmative answer to the expected cancellation between the loop terms and the one-loop anomaly. Moreover, with this computation we confirm that the one-loop tachyon amplitudes are correctly reproduced in our SFT, and we are able to determine all the remaining coupling constants left undetermined in the previous work; in particular, we show that the gauge group must be SO(2 13 = 8192). 3) - 8) The action of the present system, containing seven interaction terms, is given by S = − 1 �Ψ | ˜

title: Exploring vacuum manifold of open string field theory
abstract: The global symmetry generated by Kn is a subgroup of the stringy gauge symmetry. We explore the part of the vacuum manifold related by this symmetry. Strong evidence is presented that the analytic classical solutions to the cubic string field theory found earlier in Refs. 5) [T. Takahashi and S. Tanimoto,  (2002), 033; ] and 6) [I. Kishimoto and T. Takahashi,  (2002), 591; ] are actually related by the symmetry and, therefore, all of them describe the same tachyon vacuum. Some remaining subtlety is pointed out.

title: Tachyon vacuum of bosonic open string field theory in marginally deformed backgrounds
abstract: We consider bosonic open string field theory in marginally deformed backgrounds, which is obtained by expanding the string field around identity-based solutions associated with marginal deformations. We find a new set of string fields that satisfies the KB calgebra, but the nilpotent kinetic operator is that of the theory expanded around the identity-based marginal solution. By use of these string fields, we construct the tachyon vacuum solution in marginally deformed backgrounds. The vacuum energy density is equivalent to that of the tachyon vacuum without marginal deformations. The gauge invariant overlap is changed according to the effect of marginal deformations, as expected from known results in conformal field theory (CFT). These results suggest that the vacuum energy is zero for the identity-based marginal solutions in the original theory.