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Abstract Cosmological Black Holes as Models of Cosmological Inhomogeneities
, 2006
"... Since cosmological black holes modify the density and pressure of the surrounding universe, and introduce heat conduction, they produce simple models of cosmological inhomogeneities that can be used to study the eect of inhomogeneities on the universe's expansion. In this thesis, new cosmologi ..."
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Since cosmological black holes modify the density and pressure of the surrounding universe, and introduce heat conduction, they produce simple models of cosmological inhomogeneities that can be used to study the eect of inhomogeneities on the universe's expansion. In this thesis, new cosmological black hole solutions are obtained by generalizing the expanding KerrSchild cosmological black holes to obtain the charged case, by performing a KerrSchild transformation of the Einsteinde Sitter universe (instead of a closed universe) to obtain nonexpanding KerrSchild cosmological black holes in asymptotically
at universes, and by performing a conformal transformation on isotropic black hole spacetimes to obtain isotropic cosmological black hole spacetimes. The latter approach is found to produce cosmological black holes with energymomentum tensors that are physical throughout spacetime, unlike previous solutions for cosmological black holes, which violate the energy conditions in some region of spacetime. In addition, it is demonstrated that radiationdominated and matterdominated Einsteinde Sitter universes can be directly matched across a hypersurface of constant time, and this is used to generate the rst solutions for primordial black holes that evolve from being in radiationdominated background universes to matterdominated background universes. Finally, the Weyl curvature, volume expansion, velocity eld, shear, and acceleration are calculated for the cosii mological black holes. Since the nonisotropic black holes introduce shear, according to Raychaudhuri's equation they will tend to decrease the volume expansion of the universe. Unlike several studies that have suggested the relativistic backreaction of inhomogeneities would lead to an accelerating expansion of the universe, it is concluded that shear should be the most likely in
uence of inhomogeneities, so they should most likely decrease the universe's expansion. iii
and Statistics
, 2006
"... We analyze the consumptionportfolio selection problem of an investor facing both Brownian and jump risks. By adopting a factor structure for the asset returns and decomposing the two types of risks on a well chosen basis, we provide a new methodology for determining the optimal solution up to an im ..."
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We analyze the consumptionportfolio selection problem of an investor facing both Brownian and jump risks. By adopting a factor structure for the asset returns and decomposing the two types of risks on a well chosen basis, we provide a new methodology for determining the optimal solution up to an implicitly defined constant, which in some cases can be reduced to a fully explicit closed form, irrespectively of the number of assets available to the investor. We show that the optimal policy is for the investor to focus on controlling his exposure to the jump risk, while exploiting differences in the asset returns diffusive characteristics in the orthogonal space. We also examine the solution to the portfolio problem as the number of assets increases and the impact of the jumps on the diversification of the optimal portfolio.
AGR 05
"... Responses of soil biological processes to elevated atmospheric [CO2] and nitrogen addition in a poplar plantation ..."
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Responses of soil biological processes to elevated atmospheric [CO2] and nitrogen addition in a poplar plantation
doi:10.1112/jlms/jdm031 CELLULARIZATION OF CLASSIFYING SPACES AND FUSION PROPERTIES OF FINITE GROUPS
"... One way to understand the mod p homotopy theory of classifying spaces of finite groups is to compute their BZ/pcellularization. In the easiest cases this is a classifying space of a finite group (always a finite pgroup). If not, we show that it has infinitely many nontrivial homotopy groups. More ..."
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One way to understand the mod p homotopy theory of classifying spaces of finite groups is to compute their BZ/pcellularization. In the easiest cases this is a classifying space of a finite group (always a finite pgroup). If not, we show that it has infinitely many nontrivial homotopy groups
Whom You Know Matters: Venture Capital Networks and Investment Performance,
 Journal of Finance
, 2007
"... Abstract Many financial markets are characterized by strong relationships and networks, rather than arm'slength, spotmarket transactions. We examine the performance consequences of this organizational choice in the context of relationships established when VCs syndicate portfolio company inv ..."
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Cited by 138 (8 self)
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, but it classifies the funds' portfolio companies into six broad groups. We take a sample fund's industry specialization to be the broad Venture Economics industry group that accounts for most of its invested capital. On this basis, 46.2% of funds specialize in "Computer related" companies, 18
Akademisk avhandling för teknisk doktorsexamen vid
, 1994
"... mcmxciv This thesis deals with combinatorics in connection with Coxeter groups, finitely generated but not necessarily finite. The representation theory of groups as nonsingular matrices over a field is of immense theoretical importance, but also basic for computational group theory, where the group ..."
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mcmxciv This thesis deals with combinatorics in connection with Coxeter groups, finitely generated but not necessarily finite. The representation theory of groups as nonsingular matrices over a field is of immense theoretical importance, but also basic for computational group theory, where
Anonymous Hierarchical IdentityBased Encryption (Without Random Oracles). In: Dwork
 CRYPTO 2006. LNCS,
, 2006
"... Abstract We present an identitybased cryptosystem that features fully anonymous ciphertexts and hierarchical key delegation. We give a proof of security in the standard model, based on the mild Decision Linear complexity assumption in bilinear groups. The system is efficient and practical, with sm ..."
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Cited by 119 (10 self)
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T for an identity Id ∈ Z × p works as follows. The algorithm chooses random exponents s, s 1 , s 2 ∈ Z p , and creates the ciphertext as: Decrypt(Pvk Id , C) The decryption algorithm attempts to decrypt a ciphertext CT by computing: Proving Security. We prove security using a hybrid experiment. Let [C , C 0 , C 1
Applied and Computational Harmonic Analysis
"... This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal noncommercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or sel ..."
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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal noncommercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution
Results 1  10
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296