9,720 research outputs found
Nilpotent Networks and 4D RG Flows
Starting from a general SCFT, we study the network of
SCFTs obtained from relevant deformations by nilpotent mass
parameters. We also study the case of flipper field deformations where the mass
parameters are promoted to a chiral superfield, with nilpotent vev. Nilpotent
elements of semi-simple algebras admit a partial ordering connected by a
corresponding directed graph. We find strong evidence that the resulting fixed
points are connected by a similar network of 4D RG flows. To illustrate these
general concepts, we also present a full list of nilpotent deformations in the
case of explicit SCFTs, including the case of a single
D3-brane probing a - or -type F-theory 7-brane, and 6D conformal
matter compactified on a , as described by a single M5-brane probing a
- or -type singularity. We also observe a number of numerical
coincidences of independent interest, including a collection of theories with
rational values for their conformal anomalies, as well as a surprisingly nearly
constant value for the ratio for the entire
network of flows associated with a given UV SCFT. The
submission also includes the full dataset of theories which
can be accessed with a companion script.Comment: v2: 73 pages, 12 figures, clarifications and references adde
Optimization of resource allocation can explain the temporal dynamics and honesty of sexual signals
In species in which males are free to dynamically alter their allocation to sexual signaling over the breeding season, the optimal investment in signaling should depend on both a male’s state and the level of competition he faces at any given time. We developed a dynamic optimization model within a game‐theoretical framework to explore the resulting signaling dynamics at both individual and population levels and tested two key model predictions with empirical data on three‐spined stickleback (Gasterosteus aculeatus) males subjected to dietary manipulation (carotenoid availability): (1) fish in better nutritional condition should be able to maintain their signal for longer over the breeding season, resulting in an increasingly positive correlation between nutritional status and signal (i.e., increasing signal honesty), and (2) female preference for more ornamented males should thus increase over the breeding season. Both predictions were supported by the experimental data. Our model shows how such patterns can emerge from the optimization of resource allocation to signaling in a competitive situation. The key determinants of the honesty and dynamics of sexual signaling are the condition dependency of male survival, the initial frequency distribution of nutritional condition in the male population, and the cost of signaling
Origin and Detection of Microstructural Clustering in Fluids with Spatial-Range Competitive Interactions
Fluids with competing short-range attractions and long-range repulsions mimic
dispersions of charge-stabilized colloids that can display equilibrium
structures with intermediate range order (IRO), including particle clusters.
Using simulations and analytical theory, we demonstrate how to detect cluster
formation in such systems from the static structure factor and elucidate links
to macrophase separation in purely attractive reference fluids. We find that
clusters emerge when the thermal correlation length encoded in the IRO peak of
the structure factor exceeds the characteristic lengthscale of interparticle
repulsions. We also identify qualitative differences between the dynamics of
systems that form amorphous versus micro-crystalline clusters.Comment: 6 pages, 5 figure
INCORPORATING PREDICTIVE MAINTENANCE BEST PRACTICES INTO MARINE CORPS TRAINING AND OPERATIONS
The Marine Corps currently utilizes a traditional time-based strategy for ground equipment maintenance, conducting preventative maintenance at specified time intervals and corrective maintenance when failure occurs. In 2020, the Marine Corps initiated the transition from this maintenance strategy to a Condition Based Maintenance Plus (CBM+) strategy, which detects subcomponent anomalies in advance through data analytics so maintenance can be conducted before failure occurs. Hypothetically, CBM+ will generate increased cost-savings, reduce man-hour requirements, and improve operational availability for Marine Corps ground systems. Using a case study methodology, this project highlights best practices within the commercial mining, railroad, and heavy equipment industries by interviewing maintenance professionals and supplementing these discussions with existing literature. We then used a thematic analysis across five themes: organizational structure, asset classification, information technology (IT) infrastructure, data management, and maintenance decision making. By highlighting commonalities across the cases and evaluating best practices, we drew three key conclusions. First, some Marine Corps ground systems are not CBM+ compatible. Second, significant upgrades to existing maintenance infrastructure are necessary. Finally, CBM+ should be used as a decision-making framework to maximize cost-savings and combat readiness.Captain, United States Marine CorpsMajor, United States Marine CorpsApproved for public release. Distribution is unlimited
Spitzer Phase Curves of KELT-1b and the Signatures of Nightside Clouds in Thermal Phase Observations
We observed two full orbital phase curves of the transiting brown dwarf
KELT-1b, at 3.6um and 4.5um, using the Spitzer Space Telescope. Combined with
previous eclipse data from Beatty et al. (2014), we strongly detect KELT-1b's
phase variation as a single sinusoid in both bands, with amplitudes of
ppm at 3.6um and ppm at 4.5um, and confirm the secondary
eclipse depths measured by Beatty et al. (2014). We also measure noticeable
Eastward hotspot offsets of degrees at 3.6um and
degrees at 4.5um. Both the day-night temperature contrasts and the hotspot
offsets we measure are in line with the trends seen in hot Jupiters (e.g.,
Crossfield 2015), though we disagree with the recent suggestion of an offset
trend by Zhang et al. (2018). Using an ensemble analysis of Spitzer phase
curves, we argue that nightside clouds are playing a noticeable role in
modulating the thermal emission from these objects, based on: 1) the lack of a
clear trend in phase offsets with equilibrium temperature, 2) the sharp
day-night transitions required to have non-negative intensity maps, which also
resolves the inversion issues raised by Keating & Cowan (2017), 3) the fact
that all the nightsides of these objects appear to be at roughly the same
temperature of 1000K, while the dayside temperatures increase linearly with
equilibrium temperature, and 4) the trajectories of these objects on a Spitzer
color-magnitude diagram, which suggest colors only explainable via nightside
clouds.Comment: AJ in press. Updated to reflect the accepted versio
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