27,140 research outputs found
Forecasting Sales and Price for Existing Single-Family Homes: A VAR Model with Error Correction
In this paper we forecast demand for existing single-family housing in the United States. We first find that sales volume (sales) and median sales price (price) have unit roots. We then find that sales and price are cointegrated. We develop a vector autoregressive (VAR) model with error correction to further examine the causality between sales and price. We find that there exists a bidirectional causality relationship between sales and price. Price affects sales significantly and sales affects price weakly. With the VAR model we then forecast sales and price for existing single-family housing during the period 1991 to 1994 by using a recursive method. We find that our predictions for sales and price fit the actual data well.
A Possible Hermitian Neutrino Mixing Ansatz
Using a recent global analysis result after the precise measurement of
, a possible Herimtian neutrino mixing ansatz is discussed, the
mixing matrix is symmetric and also symmetric with respect with the second
diagonal line in the leading order. This leading order ansatz predicts
. Next, consider the hierarchy structure of the lepton
mass matrix as the origin of perturbation of the mixing matrix, we find that
this ansatz with perturbation can fit current data very well.Comment: 13 pages, 4 figure
On the Noether charge and the gravity duals of quantum complexity
The physical relevance of the thermodynamic volumes of AdS black holes to the
gravity duals of quantum complexity was recently argued by Couch et al. In this
paper, by generalizing the Wald-Iyer formalism, we derive a geometric
expression for the thermodynamic volume and relate its product with the
thermodynamic pressure to the non-derivative part of the gravitational action
evaluated on the Wheeler-DeWitt patch. We propose that this action provides an
alternative gravity dual of the quantum complexity of the boundary theory. We
refer this to "complexity=action 2.0" (CA-2) duality. It is significantly
different from the original "complexity=action" (CA) duality as well as the
"complexity=volume 2.0" (CV-2) duality proposed by Couch et al. The latter
postulates that the complexity is dual to the spacetime volume of the
Wheeler-DeWitt patch. To distinguish our new conjecture from the various
dualities in literature, we study a number of black holes in
Einstein-Maxwell-Dilation theories. We find that for all these black holes, the
CA duality generally does not respect the Lloyd bound whereas the CV-2 duality
always does. For the CA-2 duality, although in many cases it is consistent with
the Lloyd bound, we also find a counter example for which it violates the bound
as well.Comment: minor corrections, references added,29pages,7figure
- …