Life, The Universe, and Nothing: Life and Death in an Ever-Expanding Universe

Current evidence suggests that the cosmological constant is not zero, or that we live in an open universe. We examine the implications for the future under these assumptions, and find that they are striking. If the Universe is cosmological constant-dominated, our ability to probe the evolution of large scale structure will decrease with time ---presently observable distant sources will disappear on a time-scale comparable to the period of stellar burning. Moreover, while the Universe might expand forever, the integrated conscious lifetime of any civilization will be finite, although it can be astronomically long. We find that this latter result is far more general. In the absence of possible exotic and uncertain strong gravitational effects, the total information recoverable by any civilization over the entire history of our universe is finite, and assuming that consciousness has a physical computational basis, life cannot be eternal.Comment: 23 pages, latex, submitted to Ap.

Universal Limits on Computation

The physical limits to computation have been under active scrutiny over the past decade or two, as theoretical investigations of the possible impact of quantum mechanical processes on computing have begun to make contact with realizable experimental configurations. We demonstrate here that the observed acceleration of the Universe can produce a universal limit on the total amount of information that can be stored and processed in the future, putting an ultimate limit on future technology for any civilization, including a time-limit on Moore's Law. The limits we derive are stringent, and include the possibilities that the computing performed is either distributed or local. A careful consideration of the effect of horizons on information processing is necessary for this analysis, which suggests that the total amount of information that can be processed by any observer is significantly less than the Hawking-Bekenstein entropy associated with the existence of an event horizon in an accelerating universe.Comment: 3 pages including eps figure, submitted to Phys. Rev. Lett; several typos corrected, several references added, and a short discussion of w <-1 adde

Challenges in Demonstrating the Impact of Overconfidence in M&A Activity

Financial Economics,

Macro Dark Matter

Dark matter is a vital component of the current best model of our universe, $\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of Earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space. A large region of parameter space remains, most notably for nuclear-dense objects with masses in the range $55 - 10^{17}$ g and $2\times10^{20} - 4\times10^{24}$ g, although the lower mass window is closed for Macros that destabilize ordinary matter.Comment: 13 pages, 1 table, 4 figures. Submitted to MNRAS. v3: corrected small errors and a few points were made more clear, v4: included CMB bounds on dark matter-photon coupling from Wilkinson et al. (2014) and references added. Final revision matches published versio

Structural Conservation Practices in U.S. Corn Production: Evidence on Environmental Stewardship by Program Participants and Non-Participants

This study used the 2005 ERS CEAP-ARMS data for corn production to first compare key operator, field, farm, economic, and environmental characteristics of conservation program participants with non-participants, by farm-size class. We then estimate a cost-function based technology adoption model of producer decisions regarding the allocation of field-level acres between corn production and infield and perimeter-field conservation structures to examine how these conservation choices differ between program participants and non-participants, while accounting for differences in other field, farm, and environmental factors. Our null hypothesis is that the average conservation structural practice acres across U.S. corn acres supplied by growers participating in a conservation program are not different from non-participants. Infield conservation structures include terraces, grassed waterways, vegetative buffers, contour buffers, filter strips, and grade stabilization structures. Perimeter-field conservation structures include hedgerow plantings, stream-side forest and herbaceous buffers, windbreaks and herbaceous wind barriers, field borders, and critical area plantings. Because the dependent variable in this analysis is continuous, we use a Generalized Estimating Equations (GEE) procedure to estimate two models. The GEE estimation procedure (Liang and Zeger, 1986) accounts for correlation between adoption decisions measured as a continuous variable while maintaining the theoretical integrity of a multinomial discrete-choice model typically used in technology adoption studies. The cost-function models estimate field-level, producer acreage allocation decisions for corn, first, as a function of normalized production input costs (prices) and structural technology class and installation time-period attributes (Model 1), and second, as a function of Model 1 variables plus socio-environmental variables reflecting the potential influence of a variety of field, farm, and environmental characteristics (Model 2). Evidence indicates significant characteristic differences exist between conservation program participants and non-participants across U.S. corn production, that non-program factors do heavily influence producer conservation practice decisions, and that farm-size matters. In addition, results suggest that program non-participants tend to adopt infield conservation structures much more intensively while program participants emphasize the adoption of perimeter-field conservation structures. Finally, these results seem to suggest that because perimeter-field structural practices can involve differential productivity/cost effects and off-site benefits, program incentives may need to play a greater role in encouraging their adoption than they do for infield structural practices.Crop Production/Industries, Environmental Economics and Policy,

Angiolymphoid hyperplasia with eosinophilia treated with Mohs micrographic surgery

A 60-year-old healthy man presented with several enlarging, tender, spontaneously bleeding, and episodically pruritic nodules on his ear. Five agminated pink-red papulonodules of the superior postauricular sulcus were noted on examination. Pathological examination revealed a lobular dermal vascular proliferation with plump endothelial cells protruding into the lumen in a hobnail pattern, along with a dense perivascular inflammatory infiltrate composed of plasma cells, lymphocytes, and numerous eosinophils. The diagnosis of angiolymphoid hyperplasia with eosinophilia was confirmed. After discussing treatment modalities, the patient opted for Mohs micrographic surgery (MMS). Three stages of MMS were able to remove all large vessel involvement and clear the peripheral margins, but the tumor had a complex branching pattern of growth in the deep bed of the wound with numerous tiny foci remaining. Owing to risk of disfigurement, no further excision was undertaken. The area was reconstructed with a temporalis fascia flap and a full-thickness skin graft. Despite remaining microscopic disease, the patient remained without recurrence or symptoms at one year of follow up

RUSSIAN FARM ENTERPRISE PERFORMANCE AND RESTRUCTURING: A DEBT PROBLEM OR A PROFITABILITY PROBLEM?

Farm Management,

Chern-Simons action for inhomogeneous Virasoro group as an extension of three dimensional flat gravity

We initiate the study of a Chern-Simons action associated to the semi-direct sum of the Virasoro algebra with its coadjoint representation. This model extends the standard Chern-Simons formulation of three dimensional flat gravity and is similar to the higher-spin extension of three dimensional anti-de Sitter or flat gravity. The extension can also be constructed for the exotic but not for the cosmological constant deformation of flat gravity.Comment: 15 pages. Version to appear in J. of Math. Phy