Observed parity-odd CMB temperature bispectrum

Parity-odd non-Gaussianities create a variety of temperature bispectra in the cosmic microwave background (CMB), defined in the domain: $\ell_1 + \ell_2 + \ell_3 = {\rm odd}$. These models are yet unconstrained in the literature, that so far focused exclusively on the more common parity-even scenarios. In this work, we provide the first experimental constraints on parity-odd bispectrum signals in WMAP 9-year temperature data, using a separable modal parity-odd estimator. Comparing theoretical bispectrum templates to the observed bispectrum, we place constraints on the so-called nonlineality parameters of parity-odd tensor non-Gaussianities predicted by several Early Universe models. Our technique also generates a model-independent, smoothed reconstruction of the bispectrum of the data for parity-odd configurations.Comment: 17 pages, 4 figures, 1 table. Accepted for publication in JCA

The Trans-Pacific Partnership (TPP): In Brief

The Trans-Pacific Partnership (TPP) is a proposed free trade agreement (FTA) among 12 Asia-Pacific countries, with both economic and strategic significance for the United States. If approved, it would be the largest FTA in which the United States participates. The 12 countries announced the conclusion of the TPP negotiations on October 5, 2015, after several years of ongoing talks. The President released the text of the agreement and notified Congress of his intent to sign on November 5, 2015. Congress would need to pass implementing legislation for a final TPP agreement to enter into force for the United States. Such legislation would be eligible to receive expedited legislative consideration under the recent grant of Trade Promotion Authority (TPA), P.L. 114-26, if Congress determines the Administration has advanced the TPA negotiating objectives, and met various notification and consultation requirements. TPP negotiating parties include Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States, and Vietnam. Through the TPP, the participating countries seek to liberalize trade and investment and establish new rules and disciplines in the region beyond what exists in the World Trade Organization (WTO). The FTA is envisioned as a living agreement that will be open to future members and may become a vehicle to advance a wider Asia-Pacific free trade area. It is a U.S. policy response to the rapidly increasing economic and strategic linkages among Asian-Pacific nations and has become the economic centerpiece of the Administration’s “rebalance” to the region. The TPP has slowly evolved from a more limited agreement among four countries concluded in 2006 into the current 12-country FTA agreement, with the United States joining the negotiations in 2008. Japan, the most recent country to participate, joined the negotiations in 2013. This significantly increased the potential economic significance of the agreement to the United States, because Japan is the largest economy and trading partner without an existing U.S. FTA among TPP negotiating partners (thus having greater scope for trade liberalization with the United States). The United States already has FTAs with 6 of the 11 other countries participating. Malaysia and Vietnam also stand out among the TPP countries without existing U.S. FTAs, given the rapid growth in U.S. trade with the two nations over the past three decades and substantial presence of state-owned enterprises (SOEs) that will be affected by the TPP’s SOE provisions. Views on the potential impact of the agreement vary. Proponents argue that the TPP has the opportunity to boost economic growth and jobs through expanded trade and investment opportunities with negotiating partners that currently make up 37% of total U.S. goods and services trade, involves writing new trade rules and disciplines, and deepening U.S. trade and investment integration in what many see as the world’s most economically vibrant region. The agreement would eventually eliminate all tariffs on manufactured products and most agricultural goods. It also includes new trade disciplines on issues such as digital trade barriers, state-owned enterprises (SOEs), and regulatory coherence, among other provisions. Opponents voice concerns over potential job loss and competition in import-sensitive industries, and how a TPP agreement might limit U.S. ability to regulate in areas such as health, food safety, and the environment, among other concerns. The Obama Administration, joined by many analysts as well as many policymakers in the region, has argued that the strategic value of a potential TPP agreement parallels its economic value, contending that the agreement would strengthen U.S. allies and partners and reaffirm U.S. economic leadership in the region. The President has repeatedly highlighted the importance of maintaining U.S. leadership in crafting global trade rules, notably with reference to potentially alternative Chinese initiatives. China is not a party to the TPP. Others argue that past trade pacts have had a limited impact on broad foreign policy dynamics

The Trans-Pacific Partnership (TPP): Negotiations and Issues for Congress

The Trans-Pacific Partnership (TPP) is a potential free trade agreement (FTA) among 12, and perhaps more, countries (Figure 1). The United States and 11 other countries o f the Asia-Pacific region—Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, and Vietnam—are negotiating the text of the FTA. With over 20 chapters under negotiation, the TPP partners envision the agreement to be “comprehensive and high-standard,” in that they seek to eliminate tariffs and nontariff barriers to trade in goods, services, and agriculture, and to establish or expand rules on a wide range of issues including intellectual property rights, foreign direct investment, and other trade-related issues. They also strive to create a “21st-century agreement” that addresses new and cross-cutting issues presented by an increasingly globalized economy. The TPP draws congressional interest on a number of fronts. Congress would have to approve implementing legislation for U.S. commitments under the agreement to enter into force. In addition, under long-established executive-legislative practice, the Administration notifies and consults with congressional leaders, before, during, and after trade agreements have been negotiated. Furthermore, the TPP will likely affect a range of sectors and regions of the U.S. economy of direct interest to Members of Congress and could influence the shape and path of U.S. trade policy for the foreseeable future. This report examines the issues related to the proposed TPP, the state and substance of the negotiations (to the degree that the information is publicly available), the specific areas under negotiation, the policy and economic contexts in which the TPP would fit, and the issues for Congress that the TPP presents. The report will be revised and updated as events warrant

The shape of primordial non-Gaussianity and the CMB bispectrum

We present a set of formalisms for comparing, evolving and constraining primordial non-Gaussian models through the CMB bispectrum. We describe improved methods for efficient computation of the full CMB bispectrum for any general (non-separable) primordial bispectrum, incorporating a flat sky approximation and a new cubic interpolation. We review all the primordial non-Gaussian models in the present literature and calculate the CMB bispectrum up to l <2000 for each different model. This allows us to determine the observational independence of these models by calculating the cross-correlation of their CMB bispectra. We are able to identify several distinct classes of primordial shapes - including equilateral, local, warm, flat and feature (non-scale invariant) - which should be distinguishable given a significant detection of CMB non-Gaussianity. We demonstrate that a simple shape correlator provides a fast and reliable method for determining whether or not CMB shapes are well correlated. We use an eigenmode decomposition of the primordial shape to characterise and understand model independence. Finally, we advocate a standardised normalisation method for $f_{NL}$ based on the shape autocorrelator, so that observational limits and errors can be consistently compared for different models.Comment: 32 pages, 20 figure

Primordial non-Gaussianity and the CMB bispectrum

We present a new formalism, together with efficient numerical methods, to directly calculate the CMB bispectrum today from a given primordial bispectrum using the full linear radiation transfer functions. Unlike previous analyses which have assumed simple separable ansatze for the bispectrum, this work applies to a primordial bispectrum of almost arbitrary functional form, for which there may have been both horizon-crossing and superhorizon contributions. We employ adaptive methods on a hierarchical triangular grid and we establish their accuracy by direct comparison with an exact analytic solution, valid on large angular scales. We demonstrate that we can calculate the full CMB bispectrum to greater than 1% precision out to multipoles l<1800 on reasonable computational timescales. We plot the bispectrum for both the superhorizon ('local') and horizon-crossing ('equilateral') asymptotic limits, illustrating its oscillatory nature which is analogous to the CMB power spectrum

General CMB and Primordial Bispectrum Estimation I: Mode Expansion, Map-Making and Measures of f_NL

We present a detailed implementation of two bispectrum estimation methods which can be applied to general non-separable primordial and CMB bispectra. The method exploits bispectrum mode decompositions on the domain of allowed wavenumber or multipole values. Concrete mode examples constructed from symmetrised tetrahedral polynomials are given, demonstrating rapid convergence for known bispectra. We use these modes to generate simulated CMB maps of high resolution (l > 2000) given an arbitrary primordial power spectrum and bispectrum or an arbitrary late-time CMB angular power spectrum and bispectrum. By extracting coefficients for the same separable basis functions from an observational map, we are able to present an efficient and general f_NL estimator for a given theoretical model. The estimator has two versions comparing theoretical and observed coefficients at either primordial or late times, thus encompassing a wider range of models, including secondary anisotropies, lensing and cosmic strings. We provide examples and validation of both f_NL estimation methods by direct comparison with simulations in a WMAP-realistic context. In addition, we show how the full bispectrum can be extracted from observational maps using these mode expansions, irrespective of the theoretical model under study. We also propose a universal definition of the bispectrum parameter F_NL for more consistent comparison between theoretical models. We obtain WMAP5 estimates of f_NL for the equilateral model from both our primordial and late-time estimators which are consistent with each other, as well as with results already published in the literature. These general bispectrum estimation methods should prove useful for the analysis of nonGaussianity in the Planck satellite data, as well as in other contexts.Comment: 41 pages, 17 figure