The degenerate gravitino scenario

In this work, we explore the "degenerate gravitino" scenario where the mass difference between the gravitino and the lightest MSSM particle is much smaller than the gravitino mass itself. In this case, the energy released in the decay of the next to lightest sypersymmetric particle (NLSP) is reduced. Consequently the cosmological and astrophysical constraints on the gravitino abundance, and hence on the reheating temperature, become softer than in the usual case. On the other hand, such small mass splittings generically imply a much longer lifetime for the NLSP. We find that, in the constrained MSSM (CMSSM), for neutralino LSP or NLSP, reheating temperatures compatible with thermal leptogenesis are reached for small splittings of order 10^{-2} GeV. While for stau NLSP, temperatures of 4x10^9 GeV can be obtained even for splittings of order of tens of GeVs. This "degenerate gravitino" scenario offers a possible way out to the gravitino problem for thermal leptogenesis in supersymmetric theories.Comment: 27 pages, 10 figures and 1 table. Minor typos and references fixed. Matches published version in JCAP

Особливості кваліфікації злочинів у сфері використання ЕОМ (комп’ютерів), систем та комп’ютерних мереж і мереж електрозв’язку

Васильєв, А. А. Особливості кваліфікації злочинів у сфері використання ЕОМ (комп’ютерів), систем та комп’ютерних мереж і мереж електрозв’язку / А. А. Васильєв, Д. В. Пашнєв // Вісник Кримінологічної асоціації України. - 2013. - № 5. - С. 34-42.В статті визначено особливості кримінально-правової характеристики злочинів у сфері використання ЕОМ (комп’ютерів), систем та комп’ютерних мереж і мереж електрозв’язку. Розроблено окремі правила кваліфікації комп’ютерних злочинів.The article reveals some features of criminal and legal characteristics of the crimes in the sphere of usage of ECM (computers), systems, computer networks and telecommunication networks. Separate rules for the qualification of computer crimes are worked out.В статье выявлены особенности криминально-правовой характеристики преступлений в сфере использования ЭВМ (компьютеров), систем, компьютерных сетей и сетей электросвязи. Разработаны отдельные правила квалификации компьютерных преступлений

N=1 SUPER-P-BRANES in twistor-like Lorentz harmonic formulation

Unique twistor--like Lorentz harmonic formulation for all N=1 supersymmetric extended objects (super-p-branes) moving in the space--time of arbitrary dimension D (admissible for given $p$) are suggested. The equations of motion are derived, explicit form of the \kappa-symmetry transformations is presented and the classical equivalence to the standard formulation is proved. The cases with minimal world--sheet dimensions $p=1,2$, namely of D=10 heterotic string and D=11 supermembrane, are considered in details. In particular, the explicit form of irreducible \kappa-symmetry transformations for D=11 supermembrane is derived.Comment: (revized: minor changes, which was nesessary because previous version cannot be read LATEX byond Padova University), 24 pages, LATEX , DEPD/94/TH/3

On the n=4 Supersymmetry for the FRW Model

In this work we have constructed the n=4 extended local conformal time supersymmetry for the Friedmann-Robertson-Walker (FRW) cosmological models. This is based on the superfield construction of the action, which is invariant under wordline local n=4 supersymmetry with $SU(2)_{local} \otimes SU(2)_{global}$ internal symmetry. It is shown that the supersymmetric action has the form of the localized (or superconformal) version of the action for n=4 supersymmetric quantum mechanics. This superfield procedure provides a well defined scheme for including supermatter.Comment: 8 pages. Accepted for publication in Phys. Rev

Kerr Spinning Particle, Strings, and Superparticle Models

A combined model of the Kerr spinning particle and superparticle is considered. The structure of the Kerr geometry is presented in a complex form as being created by a complex source. A natural supergeneralization of this construction is obtained corresponding to a complex "supersource". Peforming a supershift to the Kerr and Kerr-Sen solutions we obtain metrics of supergravity black holes with a nonlinear realization of broken supersymmetry.Comment: minor revision, some grammatical changes and correction of the misprint before eq.(10); 13p., Latex, Talk at the International Seminar "Supersymmetry and quantum field theory" dedicated to the memory of D.V.Volkov, Kharkov, January 199

Tensor gauge fields in arbitrary representations of GL(D,R): II. Quadratic actions

Quadratic, second-order, non-local actions for tensor gauge fields transforming in arbitrary irreducible representations of the general linear group in D-dimensional Minkowski space are explicitly written in a compact form by making use of Levi-Civita tensors. The field equations derived from these actions ensure the propagation of the correct massless physical degrees of freedom and are shown to be equivalent to non-Lagrangian local field equations proposed previously. Moreover, these actions allow a frame-like reformulation a la MacDowell-Mansouri, without any trace constraint in the tangent indices.Comment: LaTeX, 53 pages, no figure. Accepted for publication in Communications in Mathematical Physics. Local Fierz-Pauli programme achieved by completing the analysis of Labastid

Generalized action principle and extrinsic geometry for N=1 superparticle

It is proposed the generalized action functional for N=1 superparticle in D=3,4,6 and 10 space-time dimensions. The superfield geometric approach equations describing superparticle motion in terms of extrinsic geometry of the worldline superspace are obtained on the base of the generalized action. The off-shell superdiffeomorphism invariance (in the rheonomic sense) of the superparticle generalized action is proved. It was demonstrated that the half of the fermionic and one bosonic (super)fields disappear from the generalized action in the analytical basis. Superparticle interaction with Abelian gauge theory is considered in the framework of this formulation. The geometric approach equations describing superparticle motion in Abelian background are obtained.Comment: 31 pages. Late

Superparticle Models with Tensorial Central Charges

A generalization of the Ferber-Shirafuji formulation of superparticle mechanics is considered. The generalized model describes the dynamics of a superparticle in a superspace extended by tensorial central charge coordinates and commuting twistor-like spinor variables. The D=4 model contains a continuous real parameter $a\geq 0$ and at a=0 reduces to the SU(2,2|1) supertwistor Ferber-Shirafuji model, while at a=1 one gets an OSp(1|8) supertwistor model of ref. [1] (hep-th/9811022) which describes BPS states with all but one unbroken target space supersymmetries. When 0<a<1 the model admits an OSp(2|8) supertwistor description, and when a>1 the supertwistor group becomes OSp(1,1|8). We quantize the model and find that its quantum spectrum consists of massless states of an arbitrary (half)integer helicity. The independent discrete central charge coordinate describes the helicity spectrum. We also outline the generalization of the a=1 model to higher space-time dimensions and demonstrate that in D=3,4,6 and 10, where the quantum states are massless, the extra degrees of freedom (with respect to those of the standard superparticle) parametrize compact manifolds. These compact manifolds can be associated with higher-dimensional helicity states. In particular, in D=10 the additional ``helicity'' manifold is isomorphic to the seven-sphere.Comment: 32 pages, LATEX, no figure

Maxwell-like Lagrangians for higher spins

We show how implementing invariance under divergence-free gauge transformations leads to a remarkably simple Lagrangian description of massless bosons of any spin. Our construction covers both flat and (A)dS backgrounds and extends to tensors of arbitrary mixed-symmetry type. Irreducible and traceless fields produce single-particle actions, while whenever trace constraints can be dispensed with the resulting Lagrangians display the same reducible, multi-particle spectra as those emerging from the tensionless limit of free open-string field theory. For all explored options the corresponding kinetic operators take essentially the same form as in the spin-one, Maxwell case.Comment: 77 pages, revised version. Erroneous interpretation and proof of the gauge-fixing procedure for mixed-symmetry fields corrected. As a consequence, the mixed-symmetry, one-particle Lagrangians are to be complemented with conditions on the divergences of the fields; all other conclusions unchanged. Additional minor changes including references added. To appear in JHE

Current Exchanges and Unconstrained Higher Spins

The (Fang-)Fronsdal formulation for free fully symmetric (spinor-) tensors rests on (gamma-)trace constraints on gauge fields and parameters. When these are relaxed, glimpses of the underlying geometry emerge: the field equations extend to non-local expressions involving the higher-spin curvatures, and with only a pair of additional fields an equivalent ``minimal'' local formulation is also possible. In this paper we complete the discussion of the ``minimal'' formulation for fully symmetric (spinor-) tensors, constructing one-parameter families of Lagrangians and extending them to (A)dS backgrounds. We then turn on external currents, that in this setting are subject to conventional conservation laws and, by a close scrutiny of current exchanges in the various formulations, we clarify the precise link between the local and non-local versions of the theory. To this end, we first show the equivalence of the constrained and unconstrained local formulations, and then identify a unique set of non-local Lagrangian equations which behave in exactly the same fashion in current exchanges.Comment: 37 pages, Latex. Typos corrected, note and references added. Final version to appear in Nucl. Phys.