19 research outputs found
S-parameter, technimesons, and phase transitions in holographic tachyon DBI models.
No full textTheoretical Physic
Palaeoshorelines of glacial Lake Kuray–Chuja, south-central Siberia: form, sediments and process
No full textGlacial lake Kuray–Chuja which occupied the Kuray and Chuja Basins during the Quaternary Period (Marine Isotope Stages 2 and 3) left distinct shoreline features around the basin margins. At the greatest extent the lake had a surface area of 2951 km2 with wind fetches up to 70 km. Wind waves constructed erosional, erosional-accumulative and accumulative strandlines, the latter including spits, tombolos, barrier beaches and offshore bars. Strandlines range in altitude between c. 1600 and 2100 m, the range in altitudes demonstrating lake level variations through time. The shoreline forms and stratigraphy are detailed. Particular attention is given to the presence of pocket beaches on rock-coasts, the alluvial strandlines of which have distinctive alongshore gradients. Although reasonably ascribed to regional differential tectonic uplift, the possibility that the local alongshore gradients are augmented as a process response to alongshore drift of sediment in a sediment-starved system of closed coastal cells is explored using a simple numerical model
The Ground Ring of N=2 Minimal String Theory
No full textWe study the N=2 string theory or the N=4 topological string on the deformed CHS background. That is, we consider the N=2 minimal model coupled to the N=2 Liouville theory. This model describes holographically the topological sector of little string theory. We use degenerate vectors of the respective N=2 Verma modules to find the set of BRST cohomologies at ghost number zero—the ground ring, and exhibit its structure. Physical operators at ghost number one constitute a module of the ground ring, so the latter can be used to constrain the S-matrix of the theory. We also comment on the inequivalence of BRST cohomologies of the N=2 string theory in different pictures
Chiral primary one-point functions in the D3-D7 defect conformal field theory
No full textJHEP is an open-access journal funded by SCOAP3 and licensed under CC BY 4.0archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2012-81 slaccitation: %%CITATION = ARXIV:1210.7015;%%archiveprefix: arXiv primaryclass: hep-th reportnumber: NORDITA-2012-81 slaccitation: %%CITATION = ARXIV:1210.7015;%%C.F.K. and D.Y. were supported in part by FNU through grant number 272-08-0329.
G.W.S. is supported by NSERC of Canada and by the Villum foundation through their
Velux Visiting Professor program
New evidence of the nonglaciated development of the northern part of the Western Siberian lowland in the Quaternary period
No full textTo solve the controversially debated problem related to the areal extent of the ice sheet in Western Siberia in the Quaternary period, we have studied the development of cold born objects of this area estimating the relationships between them in terms of cryogenic diversity. We have obtained a field of new cross data related to the development of cryogenic and glacial phenomena, their relationship, and traces they left. The research showed that, in this area, the trend of rock freezing is clearly reflected in the Quaternary formations, but there were no conditions for ice sheet development even during the cryochrons
Transport coefficients and low energy excitations of a strongly interacting holographic fluid
No full text
In this thesis, classes of strongly interacting quantum
field theories, have been studied. A non-perturbative method applied to these
theories are gauge/gravity duality or holographic duality, which map a system
of quantum field theory to a theory of gravity in higher dimensions.
This thesis focused on the transport coefficients which govern the low energy
excitations of these systems.
Development and Promotion of Science and Technology (DPST) Scholarship from the Thai government.Theoretical Physic
Strings and AdS/CFT at finite density
No full textThis thesis is devoted to applications of string theoretic methods of holography to strongly coupled phases of quantum field theories. In chapter 2 we consider a finite-density system of quarks, realized holographically by a probe brane in Anti-de Sitter space, with a non-trivial gauge field background on its world-volume. We reproduce the holographic zero-sound in the longitudinal channel of the current-current correlation function. We generalize this result to the case of a non-vanishing background magnetic field. This field leads to a gap in the zero-sound mode, which scales proportionally to the magnitude of the field when it is small. In chapter 3 we study the classical dynamics of the tachyon field in an AdS background described by the tachyon-Dirac-Born-Infeld action. By considering a black hole in AdS space and switching on a non-vanishing background gauge field we obtained a holographic model of conformal symmetry breaking in a strongly coupled system at finite temperature and charge density. In chapter 4 we provide the exact string theoretic description of a quantum field theory at finite temperature and charge densityTheoretical Physic
Modelling of the dissolution and reprecipitation of uranium under oxidising conditions in the zone of shallow groundwater circulation
No full textGeneric hydrochemical modelling of a grantoid-groundwater system, using the Russian software "HydroGeo", has been carried out with an emphasis on simulating the accumulation of uranium in the aqueous phase. The baseline model run simulates shallow granitoid aquifers (U content 5 ppm) under conditions broadly representative of southern Norway and southwestern Siberia: i.e. temperature 10 °C, equilibrated with a soil gas partial CO2 pressure (PCO2, open system) of 10(-2.5) atm. and a mildly oxidising redox environment (Eh = +50 mV). Modelling indicates that aqueous uranium accumulates in parallel with total dissolved solids (or groundwater mineralisation M - regarded as an indicator of degree of hydrochemical evolution), accumulating most rapidly when M = 550-1000 mg L(-1). Accumulation slows at the onset of saturation and precipitation of secondary uranium minerals at M = c. 1000 mg L(-1) (which, under baseline modelling conditions, also corresponds approximately to calcite saturation and transition to Na-HCO3 hydrofacies). The secondary minerals are typically "black" uranium oxides of mixed oxidation state (e.g. U3O7 and U4O9). For rock U content of 5-50 ppm, it is possible to generate a wide variety of aqueous uranium concentrations, up to a maximum of just over 1 mg L(-1), but with typical concentrations of up to 10 μg L(-1) for modest degrees of hydrochemical maturity (as indicated by M). These observations correspond extremely well with real groundwater analyses from the Altai-Sayan region of Russia and Norwegian crystalline bedrock aquifers. The timing (with respect to M) and degree of aqueous uranium accumulation are also sensitive to Eh (greater mobilisation at higher Eh), uranium content of rocks (aqueous concentration increases as rock content increases) and PCO2 (low PCO2 favours higher pH, rapid accumulation of aqueous U and earlier saturation with respect to uranium minerals)
