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Dawid Maskalaniec

Publications and source records attributed to Dawid Maskalaniec.

4 recordsLinked to original sources

Eikonal Scattering of Two D0-branes with Graviton Emission

We study the emission of a massless closed-string state in the scattering of two D0-branes using the boundary-state formalism. We compute the corresponding five-point amplitudes for graviton and dilaton emission in bosonic string theory and in type II superstring theory, and analyze their field-theory limit. For nonzero impact parameter, the resulting amplitudes are reproduced by an independent calculation in the worldline formulation of the corresponding low-energy theory.

hep-th

Non-Lorentzian Supergravity from Matrix Theory

It was recently shown that the decoupling limits leading to matrix (gauge) theories on D-branes give rise to non-Lorentzian target space geometries. Perturbatively, matrix theory describes a quantum gravity theory whose low-energy supergravity description exhibits non-Lorentzian behavior. Focusing on the D-particle case associated with the Banks-Fischler-Shenker-Susskind matrix theory, and using techniques from ambitwistor string theory, we show evidence that the dynamics of this non-Lorentzian gravity should be related to anomalies in the current algebra of the associated fundamental string worldsheet theory. At large N, the D-particle backreaction deforms the non-Lorentzian supergravity to the Lorentzian IIA theory, providing a holographic description of the BFSS matrix theory. At a moderately large N such that the D-particles decouple at the leading order, this non-Lorentzian supergravity maps holographically to the leading-order contribution of weakly coupled bulk gravity. This approximately non-Lorentzian regime is related to the null reduction of eleven-dimensional supergravity. Within the non-Lorentzian supergravity, non-trivial dynamics arises from the backreaction of extended brane objects that form BPS states with the D-particles. Finally, we generalize these results to other D-brane and string soliton holographic constructions.

hep-th

Hawking radiation far away from the event horizon

We study particle production in Vaidya spacetime. Using the WKB approximation, the distribution of Hawking radiation is calculated without the near-horizon approximation, which leads to finite corrections to the purely thermal spectrum. We extend our analysis to extremal and non-extremal Reissner-Nordstr\"om and Kerr black holes. Our results can be understood in terms of a thermodynamic toy model, where one regards Hawking radiation as Unruh radiation perceived by observers outside of the black hole. Moreover, we extend the model to incorporate the backreaction of Hawking quanta on spacetime geometry. Our study suggests that the backreaction may prevent the formation of the event horizon and spacetime singularity.

gr-qc

Hierarchy and robustness of multilevel two-time temporal quantum correlations

Quantum steering refers to correlations that can be classified as intermediate between entanglement and Bell nonlocality. Every state exhibiting Bell nonlocality exhibits also quantum steering and every state exhibiting quantum steering is also entangled. In low dimensional cases similar hierarchical relations have been observed between the temporal counterparts of these correlations. Here, we study the hierarchy of such temporal correlations for a general multilevel quantum system. We demonstrate that the same hierarchy holds for two definitions of state over time. In order to compare different types of temporal correlations, we show that temporal counterparts of Bell nonlocality and entanglement can be quantified with a temporal nonlocality robustness and temporal entanglement robustness. Our numerical result reveal that in contrast to temporal steering, for temporal nonlocality to manifest itself we require the initial state not to be in a completely mixed state.

quant-ph