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Frithjof Karsch - One of the best experts on this subject based on the ideXlab platform.
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The spatial string tension and dimensional reduction in QCD
Physical Review D, 2008Co-Authors: M. Cheng, Shouvik Datta, Robert D Mawhinney, Olaf Kaczmarek, Frithjof Karsch, Edwin Laermann, J. Van Der Heide, Kay Huebner, J. Liddle, C. MiaoAbstract:We calculate the spatial string tension in (2+1) flavor QCD with physical strange quark mass and almost physical light quark masses using lattices with Temporal Extent N_tau=4,6 and 8. We compare our results on the spatial string tension with predictions of dimensionally reduced QCD. This suggests that also in the presence of light dynamical quarks dimensional reduction works well down to temperatures 1.5T_c.
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the qcd equation of state with almost physical quark masses
Physical Review D, 2008Co-Authors: Michael Cheng, Shouvik Datta, Janus Heide, C K Jung, Norman H Christ, Olaf Kaczmarek, Frithjof Karsch, Edwin Laermann, Robert D MawhinneyAbstract:We present results on the equation of state in QCD with two light quark flavors and a heavier strange quark. Calculations with improved staggered fermions have been performed on lattices with Temporal Extent N{sub {tau}}=4 and 6 on a line of constant physics with almost physical quark mass values; the pion mass is about 220 MeV, and the strange quark mass is adjusted to its physical value. High statistics results on large lattices are obtained for bulk thermodynamic observables, i.e. pressure, energy and entropy density, at vanishing quark chemical potential for a wide range of temperatures, 140 MeV{<=}T{<=}800 MeV. We present a detailed discussion of finite cutoff effects which become particularly significant for temperatures larger than about twice the transition temperature. At these high temperatures we also performed calculations of the trace anomaly on lattices with Temporal Extent N{sub {tau}}=8. Furthermore, we have performed an extensive analysis of zero temperature observables including the light and strange quark condensates and the static quark potential at zero temperature. These are used to set the temperature scale for thermodynamic observables and to calculate renormalized observables that are sensitive to deconfinement and chiral symmetry restoration and become order parameters in the infinite and zeromore » quark mass limits, respect0011ive.« less
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Infinite temperature limit of meson spectral functions calculated on the lattice
Physical Review D, 2003Co-Authors: Frithjof Karsch, Edwin Laermann, S. Stickan, Peter PetreczkyAbstract:We analyze the cutoff dependence of mesonic spectral functions calculated at finite temperature on Euclidean lattices with a finite Temporal Extent. In the infinite temperature limit we present analytic results for lattice spectral functions calculated with standard Wilson fermions as well as a truncated perfect action. We explicitly determine the influence of "Wilson doublers" on the high momentum structure of the mesonic spectral functions and show that this cutoff effect is strongly suppressed when using an improved fermion action.
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SU(3) Latent Heat and Surface Tension from Tree Level and Tadpole Improved Actions
Physics Letters B, 1997Co-Authors: B. Beinlich, Frithjof Karsch, A. PeikertAbstract:We analyze the latent heat and surface tension at the SU(3) deconfinement phase transition with tree level and tadpole improved Symanzik actions on lattices with Temporal Extent $N_\tau = 3$ and 4 and spatial Extent $N_\sigma/ N_\tau = 4$, 6 and 8. In comparison to the standard Wilson action we do find a drastic reduction of cut-off effects already with tree level improved actions. On lattices with Temporal Extent $N_\tau=4$ results for the surface tension and latent heat obtained with a tree level improved action agree well with those obtained with a tadpole improved action. A comparison with $N_\tau=3$ calculations, however, shows that results obtained with tadpole action remain unaffected by cut-off effects even on this coarse lattice, while the tree level action becomes sensitive to the cut-off. For the surface tension and latent heat we find $\sigma_I/ T_c^3 = 0.0155~(16)$ and $\Delta\epsilon/T_c^4 = 1.40~(9)$, respectively.
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thermodynamics of su 3 lattice gauge theory
Nuclear Physics, 1996Co-Authors: G Boyd, Frithjof Karsch, Edwin Laermann, Jurgen Engels, C Legeland, M Lutgemeier, Bengt PeterssonAbstract:The pressure and the energy density of the SU(3) gauge theory are calculated on lattices with Temporal Extent N-tau = 4, 6 and 8 and spatial Extent N-sigma = 16 and 32. The results are then extrapolated to the continuum limit. In the investigated temperature range up to five times T-c we observe a 15% deviation from the ideal gas limit. We also present new results for the critical temperature on lattices with Temporal Extent N, = 8 and 12. At the corresponding critical couplings the string tension is calculated on 32(4) lattices to fix the temperature scale. An extrapolation to the continuum limit yields T-c/root sigma = 0.629(3). We furthermore present results on the electric and magnetic condensates as well as the temperature dependence of the spatial string tension, These observables suggest that the temperature dependent running coupling remains large even at T similar or equal to 5T(c). For the spatial string tension we find root sigma(s)/T = 0.566(13)g(2)(T) with g(2)(5T(c)) similar or equal to 1.5.
Ramesh Jain - One of the best experts on this subject based on the ideXlab platform.
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VISUAL - Complex Visual Activity Recognition Using a Temporally Ordered Database
Lecture Notes in Computer Science, 1999Co-Authors: Shailendra K. Bhonsle, Simone Santini, Amarnath Gupta, Marcel Worring, Ramesh JainAbstract:We propose using a Temporally ordered database for complex visual activity recognition. We use a Temporal precedence relation together with the assumption of fixed bounded Temporal uncertainty of occurrence time of an atomic activity and comparatively large Temporal Extent of the complex activity. Under these conditions we identify the Temporal structure of complex activities as a semiorder and design a database that has semiorder as its data model. A query algebra is then defined for this data model.
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complex visual activity recognition using a Temporally ordered database
Lecture Notes in Computer Science, 1999Co-Authors: Shailendra K. Bhonsle, Simone Santini, Amarnath Gupta, Marcel Worring, Ramesh JainAbstract:We propose using a Temporally ordered database for complex visual activity recognition. We use a Temporal precedence relation together with the assumption of fixed bounded Temporal uncertainty of occurrence time of an atomic activity and comparatively large Temporal Extent of the complex activity. Under these conditions we identify the Temporal structure of complex activities as a semiorder and design a database that has semiorder as its data model. A query algebra is then defined for this data model.
Edwin Laermann - One of the best experts on this subject based on the ideXlab platform.
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The spatial string tension and dimensional reduction in QCD
Physical Review D, 2008Co-Authors: M. Cheng, Shouvik Datta, Robert D Mawhinney, Olaf Kaczmarek, Frithjof Karsch, Edwin Laermann, J. Van Der Heide, Kay Huebner, J. Liddle, C. MiaoAbstract:We calculate the spatial string tension in (2+1) flavor QCD with physical strange quark mass and almost physical light quark masses using lattices with Temporal Extent N_tau=4,6 and 8. We compare our results on the spatial string tension with predictions of dimensionally reduced QCD. This suggests that also in the presence of light dynamical quarks dimensional reduction works well down to temperatures 1.5T_c.
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the qcd equation of state with almost physical quark masses
Physical Review D, 2008Co-Authors: Michael Cheng, Shouvik Datta, Janus Heide, C K Jung, Norman H Christ, Olaf Kaczmarek, Frithjof Karsch, Edwin Laermann, Robert D MawhinneyAbstract:We present results on the equation of state in QCD with two light quark flavors and a heavier strange quark. Calculations with improved staggered fermions have been performed on lattices with Temporal Extent N{sub {tau}}=4 and 6 on a line of constant physics with almost physical quark mass values; the pion mass is about 220 MeV, and the strange quark mass is adjusted to its physical value. High statistics results on large lattices are obtained for bulk thermodynamic observables, i.e. pressure, energy and entropy density, at vanishing quark chemical potential for a wide range of temperatures, 140 MeV{<=}T{<=}800 MeV. We present a detailed discussion of finite cutoff effects which become particularly significant for temperatures larger than about twice the transition temperature. At these high temperatures we also performed calculations of the trace anomaly on lattices with Temporal Extent N{sub {tau}}=8. Furthermore, we have performed an extensive analysis of zero temperature observables including the light and strange quark condensates and the static quark potential at zero temperature. These are used to set the temperature scale for thermodynamic observables and to calculate renormalized observables that are sensitive to deconfinement and chiral symmetry restoration and become order parameters in the infinite and zeromore » quark mass limits, respect0011ive.« less
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Infinite temperature limit of meson spectral functions calculated on the lattice
Physical Review D, 2003Co-Authors: Frithjof Karsch, Edwin Laermann, S. Stickan, Peter PetreczkyAbstract:We analyze the cutoff dependence of mesonic spectral functions calculated at finite temperature on Euclidean lattices with a finite Temporal Extent. In the infinite temperature limit we present analytic results for lattice spectral functions calculated with standard Wilson fermions as well as a truncated perfect action. We explicitly determine the influence of "Wilson doublers" on the high momentum structure of the mesonic spectral functions and show that this cutoff effect is strongly suppressed when using an improved fermion action.
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thermodynamics of su 3 lattice gauge theory
Nuclear Physics, 1996Co-Authors: G Boyd, Frithjof Karsch, Edwin Laermann, Jurgen Engels, C Legeland, M Lutgemeier, Bengt PeterssonAbstract:The pressure and the energy density of the SU(3) gauge theory are calculated on lattices with Temporal Extent N-tau = 4, 6 and 8 and spatial Extent N-sigma = 16 and 32. The results are then extrapolated to the continuum limit. In the investigated temperature range up to five times T-c we observe a 15% deviation from the ideal gas limit. We also present new results for the critical temperature on lattices with Temporal Extent N, = 8 and 12. At the corresponding critical couplings the string tension is calculated on 32(4) lattices to fix the temperature scale. An extrapolation to the continuum limit yields T-c/root sigma = 0.629(3). We furthermore present results on the electric and magnetic condensates as well as the temperature dependence of the spatial string tension, These observables suggest that the temperature dependent running coupling remains large even at T similar or equal to 5T(c). For the spatial string tension we find root sigma(s)/T = 0.566(13)g(2)(T) with g(2)(5T(c)) similar or equal to 1.5.
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Equation of state in the quark gluon plasma
Nuclear Physics B - Proceedings Supplements, 1996Co-Authors: Edwin LaermannAbstract:Results from quenched simulations of QCD at finite temperature are presented. We calculated pressure and energy density. With the standard Wilson action we worked on several large lattices, with Temporal Extent Nτ = 4, 6 and 8 and spatial Extent Nσ = 16 and 32. This enables to control finite lattice spacing effects and to extrapolate the results to the continuum limit. We find a deviation from ideal gas behaviour of about 15%, even at temperatures as high as T ∼ 5Tc. A calculation of the critical temperature on lattices with Temporal Extent Nτ = 8 and 12 and the string tension on 324 lattices at the corresponding critical couplings is performed to fix the temperature scale. An extrapolation to the continuum limit yields Tc/√σ = 0.629(3). These results are then compared to simulations with improved lattice actions. We can demonstrate that at high temperatures the cut-off effects can be reduced considerably.
Shailendra K. Bhonsle - One of the best experts on this subject based on the ideXlab platform.
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VISUAL - Complex Visual Activity Recognition Using a Temporally Ordered Database
Lecture Notes in Computer Science, 1999Co-Authors: Shailendra K. Bhonsle, Simone Santini, Amarnath Gupta, Marcel Worring, Ramesh JainAbstract:We propose using a Temporally ordered database for complex visual activity recognition. We use a Temporal precedence relation together with the assumption of fixed bounded Temporal uncertainty of occurrence time of an atomic activity and comparatively large Temporal Extent of the complex activity. Under these conditions we identify the Temporal structure of complex activities as a semiorder and design a database that has semiorder as its data model. A query algebra is then defined for this data model.
-
complex visual activity recognition using a Temporally ordered database
Lecture Notes in Computer Science, 1999Co-Authors: Shailendra K. Bhonsle, Simone Santini, Amarnath Gupta, Marcel Worring, Ramesh JainAbstract:We propose using a Temporally ordered database for complex visual activity recognition. We use a Temporal precedence relation together with the assumption of fixed bounded Temporal uncertainty of occurrence time of an atomic activity and comparatively large Temporal Extent of the complex activity. Under these conditions we identify the Temporal structure of complex activities as a semiorder and design a database that has semiorder as its data model. A query algebra is then defined for this data model.
E. R. Lutman - One of the best experts on this subject based on the ideXlab platform.
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The spatial and Temporal Extent of chlorine activation by polar stratospheric clouds in the northern hemisphere winters of 1988/89 and 1991/92
Geophysical Research Letters, 1994Co-Authors: A. R. Mackenzie, Bjørn M. Knudsen, Roderic L. Jones, E. R. LutmanAbstract:A trajectory-based analysis of the northern hemisphere lower stratospheres of 1988/89 and 1991/92, from 30°N to the pole, has been carried out, allowing estimates of the area subject to chlorine activation by polar stratospheric clouds to be made. In both winters a significant area is covered by activated air (i.e., air subject to temperatures cold enough for polar stratospheric cloud formation up to 20 days previously). Activated air in the middle latitudes is a combination of the temporary displacement of vortical air equatorward and in situ activation of extra-vortical air. Relative to 1988/89, 1991/92 shows increased activation in the middle latitudes. This was due to a displacement of low temperatures towards lower values of potential vorticity by an extreme anticyclonic forcing event.
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the spatial and Temporal Extent of chlorine activation by polar stratospheric clouds in the northern hemisphere winters of 1988 89 and 1991 92
Geophysical Research Letters, 1994Co-Authors: A. R. Mackenzie, Bjørn M. Knudsen, Roderic L. Jones, E. R. LutmanAbstract:A trajectory-based analysis of the northern hemisphere lower stratospheres of 1988/89 and 1991/92, from 30°N to the pole, has been carried out, allowing estimates of the area subject to chlorine activation by polar stratospheric clouds to be made. In both winters a significant area is covered by activated air (i.e., air subject to temperatures cold enough for polar stratospheric cloud formation up to 20 days previously). Activated air in the middle latitudes is a combination of the temporary displacement of vortical air equatorward and in situ activation of extra-vortical air. Relative to 1988/89, 1991/92 shows increased activation in the middle latitudes. This was due to a displacement of low temperatures towards lower values of potential vorticity by an extreme anticyclonic forcing event.
