531 research outputs found
Ghostbusters in supergravity
supergravity is known to contain a ghost mode associated with
higher-derivative terms if it contains with greater than two.We
remove the ghost in supergravity by introducing auxiliary gauge field to
absorb the ghost. We dub this method as the ghostbuster
mechanism~\cite{Fujimori:2016udq}. We show that the mechanism removes the ghost
supermultiplet but also terms including with , after integrating
out auxiliary degrees of freedom. For pure supergravity case, there appears an
instability in the resultant scalar potential. We then show that the
instability of the scalar potential can be cured by introducing matter
couplings in such a way that the system has a stable potential.Comment: 24 pages, v2: comments, references, new section added, version
published in JHE
Application of Sturm's theorem to marginal stable circular orbits of a test body in spherically symmetric and static spacetimes
In terms of Sturm's theorem, we reexamine a marginal stable circular orbit
(MSCO) such as the innermost stable circular orbit (ISCO) of a timelike
geodesic in any spherically symmetric and static spacetime. MSCOs for some of
exact solutions to the Einstein's equation are discussed. Strum's theorem is
explicitly applied to the Kottler (often called Schwarzschild-de Sitter)
spacetime. Moreover, we analyze MSCOs for a spherically symmetric, static and
vacuum solution in Weyl conformal gravity.Comment: 6 pages, 1 figure, accepted by EPL (Europhysics Letters). arXiv admin
note: text overlap with arXiv:1410.626
Lubrication pressure model in a non-negligible gap for fluid permeation through a membrane with finite permeability
Shintaro Takeuchi, Toshiaki Fukada, Shuji Yamada, Suguru Miyauchi, and Takeo Kajishima, "Lubrication pressure model in a non-negligible gap for fluid permeation through a membrane with finite permeability", Physical Review Fluids, 6(11), 114101, https://doi.org/10.1103/PhysRevFluids.6.114101
Acute and Prolonged Effects of Dermal Suction on Joint Range of Motion and Passive Muscle Stiffness: A Preliminary Study
This study aimed to investigate the acute and prolonged effects of dermal suction on joint range of motion (ROM) and passive muscle stiffness. Eight-minute dermal suction was prescribed for the quadriceps femoris in 15 participants. Hip extension ROM, knee flexion ROM, and passive muscle stiffness of the rectus femoris (RF) and vastus lateralis (VL) were measured before and immediately, 30 min, 60 min, 120 min, 24 h, and 48 h after dermal suction. Passive muscle stiffness was measured using shear wave elastography. Hip extension ROM significantly increased immediately (p = 0.032), 60 min (p = 0.029), and 120 min (p = 0.031) after dermal suction compared with before dermal suction; however, it was not significantly different at 30 min, 24 h, and 48 h after dermal suction (p > 0.05). Passive muscle stiffness of the RF and VL and knee flexion ROM did not significantly change at any measurement time compared with before dermal suction (p > 0.05). Our preliminary results suggest that dermal suction improves hip extension ROM immediately after dermal suction of the quadriceps femoris, followed by a return to the pre-prescription level 30 min after. However, the effect was prolonged for 120 min and disappeared before 24 h
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