Long String Scattering in c = 1 String Theory

We study the scattering of long strings in c = 1 string theory, both in the worldsheet description and in the non-singlet sector of the dual matrix quantum mechanics. From the worldsheet perspective, the scattering amplitudes of long strings are obtained from a decoupling limit of open strings amplitudes on FZZT branes, which we compute by integrating Virasoro conformal blocks along with structure constants of boundary Liouville theory. In particular, we study the tree level amplitudes of (1) a long string decaying by emitting a closed string, and (2) the scattering of a pair of long strings. We show that they are indeed well defined as limits of open string amplitudes, and that our results are in striking numerical agreement with computations in the adjoint and bi-adjoint sectors of the dual matrix model (based on proposals of Maldacena and solutions due to Fidkowski), thereby providing strong evidence of the duality.Comment: 42 pages, 18 figure

The c=1 String Theory S-Matrix Revisited

We revisit the perturbative S-matrix of c=1 string theory from the worldsheet perspective. We clarify the origin of the leg pole factors, the non-analyticity of the string amplitudes, and the validity as well as limitations of earlier computations based on resonance momenta. We compute the tree level 4-point amplitude and the genus one 2-point reflection amplitude by numerically integrating Virasoro conformal blocks with DOZZ structure constants on the sphere and on the torus, with sufficiently generic complex Liouville momenta, and find agreement with known answers from the c=1 matrix model.Comment: 32 pages, 7 figures; footnote and references added, typos correcte

Airborne Doppler Radar Observations of PyroCu/Cb Plume Kinematics and Thermodynamics During the 2016 Pioneer Fire

During a period of explosive growth of the Pioneer Fire (Idaho, August 2016), deep pyroconvective plumes were sampled by aircraft. The research aircraft was equipped with both remote sensing and in situ instrumentation, including a W-Band Doppler radar which provided high-resolution vertical velocity retrievals from within the developing pyrocumulus. Being the first direct observations of vertical velocity within a pyrocumulus cloud, they have provided unique insights into the dynamical processes governing pyroconvective environments, with important implications for the fire modeling community. The observations were quality-controlled and corrected for issues such as Doppler velocity aliasing, and the plume’s kinematic structure was examined and contextualized using flight-level and surface thermodynamic data collected by the Boise National Weather Service, RAWS observations, and NEXRAD radar-derived plume echo tops. The analyses indicated an extreme pyroconvective environment, with updrafts approaching 60 m s-1 several kilometers above ground level. Interestingly, the observations yielded no secondary peak in vertical velocity aloft linked to latent heat release from condensation. Moreover, updraft magnitude was found to increase with height above the surface and below the condensation level. A wide updraft core acting to isolate the plume center from lateral entrainment processes is hypothesized as a possible explanation for the observed characteristics of the vertical velocity profiles

Massive atmospheric sulfur loading of the AD 1600 Huaynaputina eruption and implications for petrologic sulfur estimates.

International audienceWe combine petrological, analytical, and thermodynamical data to constrain the sulfur yield of the AD 1600 Huaynaputina eruption which has been associated with the largest Earth's temperature shift in the last 600 years. The calculated amount of S (26–55 Tg), partly overlaps, but ranges to almost twice the amount estimated from ice-core data (16–32 Tg), the higher values of our estimate probably reflect that not all S released by the eruption reached the stratosphere. Our study also shows that it is possible to estimate the atmospheric sulfur loading from the volcanic products themselves, which opens the possibility to explore volcano-climate links beyond the time period covered by ice-core archive

Petrological and experimental constraints on the pre-eruption conditions of holocene dacite from volcan San Pedro (36°S, Chilean Andes)and the importance of sulphur in silicic subduction-related magmas.

We present an experimental and petrological study aimed at estimating the pre-eruptive conditions of a Holocene dacitic lava from Volcán San Pedro (36°S, Chilean Andes). Phase-equilibrium experiments were performed at temperatures (T) from 800 to 950°C, and mainly at 200 MPa, but also at 55, 150, and 406 MPa. Oxygen fugacity (fO2) ranged from the Ni-NiO buffer (NNO) to 3*5 log units above (NNO + 3*5), and water contents from ~3 to ~6 wt %. We also report several experiments where we added sulphur (0*1-1 wt % S) to the dacite. The main mineral assemblage of the dacite (hornblende + orthopyroxene + plagioclase) is stable at 200 ± 50 MPa, 850 ± 10°C, with 4*5-5*5 wt % H2O in the melt, and at fO2 of NNO + 1*2 ± 0*2, in accord with the crystallinity, mineral proportions, and T-fO2 determination from Fe-Ti oxides of the lava. However, biotite, which is also present in the dacite, is stable at these same T-fO2 conditions only in experiments with >0*1 wt % S added. This result is in accord with the occurrence of pyrrhotite in the lava, and with the presence of S in glass inclusions and biotite (~300 ppm, and up 170 ppm, respectively). Moreover, the zoning patterns and compositions of plagioclase phenocrysts together with the presence of high-temperature minerals (e.g. clinopyroxene) in the lava suggest that the petrological history of the dacite is more complex than a single near-equilibrium crystallization stage, and could be explained by short-lived (<100 years) temperature fluctuations (~50°C) in the magma reservoir

The S-Matrix of 2D Type 0B String Theory Part 2: D-Instanton Effects

We study the effect of D-instantons on closed string scattering amplitudes in the two-dimensional type 0B string theory from the worldsheet perspective. We find that the contribution from a pair of D-instanton and anti-D-instanton to the closed string reflection amplitude, with a suitable contour prescription for the integration over the D-instanton moduli space, agrees with the corresponding leading non-perturbative corrections in the proposed dual matrix quantum mechanics. This analysis is further extended to thermal observables defined at finite temperature. The infrared divergence in charged processes is understood through the measure factor for charged D-instantons, and can be treated with spacetime dimensional regularization.Comment: 30 pages, 3 figures, 1 tabl