報告人：封東來，復旦大學
時間： 11月17日（周四）16:00
單位：清華大學物理系
地點：理科樓鄭裕彤大講堂
強關聯電子體系是有強電子間相互作用的d與f電子體系, 其往往具有極為豐富的物性與複雜的相圖。在本報告中我將通過幾個例子指出, 強關聯電子體系中這些複雜行為大多源自電子巡遊性與局域性之間的競爭與合作, 而要理解強關聯體系, 關鍵就是找出其中電子巡遊性與局域性的競爭與合作的具體表現形式。
對於d電子體系, 這一競爭又集中表現為所謂Mott物理, 如銅氧化物高溫超導就可認為由載流子摻雜的Mott絕緣體而來。而通過電子摻雜具有強自旋軌道耦合的5d電子Mott絕緣體, Sr2IrO4, 我們用掃瞄隧道顯微鏡(STM), 發現了該體系存在50K左右的高溫超導的跡象。在鐵砷和鐵硒兩大類鐵基超導中, 我們通過角分辨光電子能譜(ARPES)測量發現, 不同形式的摻雜過程及其紛繁相圖, 其真正改變的關鍵參數是體系能帶寬度, 即電子巡遊性與局域相互作用的相對強度. 從帶寬調控的Mott物理出發, 我們可統一理解鐵基超導相圖。據此可以設想, 從Mott物理出發, 可能就已知高溫超導體系建立一個統一的圖像。 而f電子體系的巡遊性與局域性之爭集中表現在f電子自身的巡遊性和局域性的相互轉化, 既可是在外場下的轉化(可導致量子相變), 又可是隨著溫度的轉化。我們用ARPES詳細地揭示了CeCoIn5中f電子行為隨溫度演化的微觀過程, 澄清了有關Kondo Lattice的實驗圖像。
報告人：孟傑，中科院高能物理所
時間： 11月16日（周三）10:30
單位：中國科學院大學
地點：雁棲湖校區教1-405
手性對稱型在自然界中廣泛存在，如人類的手，某些化學和藥物分子以及海螺殼等都有手徵性。原子核層次的手性對稱性概念於1997年提出，隨後成為核物理研究的熱點問題。報告簡要介紹原子核中的手性對稱性概念、手性原子核的識別、獲得手性原子核的途徑、新的理論和試驗研究進展，以及中國領導的合作組等最新發現的原子核中手性和空間反射對稱性的聯立自發破缺的證據等，並對未來理論和實驗需解決的問題進行了簡單小結。
報告人：武強，浙江工業大學
時間： 11月16日（周三）15:30
單位：北京師範大學物理學系
地點：物理樓106
圈量子引力理論優雅地解決了宇宙大爆炸的奇點難題，同時也提供了一個早期宇宙的前暴脹（pre-inflation）機制。而最近日益發展的天文觀測使得驗證各種早期宇宙模型甚至量子引力理論成為可能。本次報告我將介紹圈量子引力理論對宇宙原初漲落功率譜的影響，同時使用我們最近發展的均勻漸近近似方法（uniform asymptotic approximation method ）計算出功率譜和譜指數的解析表達式，並且使用CMB等觀測數據對圈量子引力理論參數進行限制。
4Physics of the Cosmological Collider
報告人：Yi Wang，Hong Kong University of Science and Technology
時間： 11月16日（周三）15:30
單位：中科院理論物理研究所
地點：322報告廳
We discuss how the primordial universe can be used to probe high energy physics. For this purpose, the following three topics will be covered: (1) An overview of cosmological correlation functions (non-Gaussianities). (2) Using inflation as a collider to probe the particle physics Standard Model and BSM physics. (3) Distinguishing inflation and alternative-to-inflation models from the outcome of the cosmological collider.
5Novel Properties of Some Atomic Clusters and Their Assemblies
報告人：王廣厚，南京大學
時間： 11月17日（周四）10:00
單位：北京師範大學物理學系
地點：物理樓106
Atomic clusters consist of a few to thousands of atoms and/or molecules, and attract a great attention in nanoscience and nanotechnology since they can be used as building blocks to assemble various kinds of nanostructures with novel properties. One of strategies for growing nanostructures with cluster beams consists in depositing low-energy particles. Ideally, by depositing the clusters with low kinetic energies, one would like to conserve the memory of the free-cluster phase to form thin films with their original properties. Since the kinetic energy is of the order of eV per cluster, i.e., a few meV per atom, which is negligible compared to the binding energy of an atom in the cluster, no fragmentation of the clusters is expected upon impact on the substrate.
6The information content of the power spectrum and bispectrum
報告人：Kwan Chuen Chan，Institut de Ciencies de l』Espai
時間： 11月17日（周四）14:00
單位：清華大學物理系
地點：蒙民偉科技南樓S727
To interpret the cosmological data correctly, we need not only accurate measurements of the mean quantities, such as the power spectrum and bispectrum, but also the covariance of the data. I will discuss the covariance matrix of the dark matter and halo power spectrum and bispectrum. Using a large suite of simulations (~5000), the covariance of the power spectrum and bispectrum of the dark matter and halo are measured. This is the first time that the bispectrum covariance has been quantified with such large simulation set. Perturbation theory and the Poisson model are used to model the covariance. Armed with the accurate covariance measured from simulations, we assess the information content of the power spectrum and bispectrum. This is timely because as the 2-point statistics has been well explored and the bispectrum becomes the next frontier. It is crucial to access how much information one can gain by going beyond the 2-point statistics. We find that the signal-to-noise of the power spectrum and bispectrum are significantly lower than the estimates based on the Gaussian covariance. In particular, while the Gaussian estimate suggests that the information content of the bispectrum surpasses that of the power spectrum at k ~ 0.2 h/Mpc, when the non-Gaussian covariance is taken into account, this happens only at k ~ 1 h/Mpc.
7Star formation rates and luminosity functions in the low-redshift Universe
報告人：Lingyu Wang，University of Groningen
時間： 11月17日（周四）16:00
單位：北京大學科維理天文與天體物理研究所
地點：KIAA-PKU Auditorium
The cosmic star-formation history is a key constraint on theoretical models of galaxy formation and evolution. However, currently we do not know whether the mismatch between some models and observations signals a true failure of the model due to the level of systematic uncertainties in the star-formation tracers. In the first part of my talk, I will present a critical look at the most commonly used star-formation rate indicators by exploiting the impressive and well-vetted GAMA multi-wavelength database.
報告人：李海波，中科院高能物理研究所
時間： 11月18日（周五）13:30
單位：中國科學院大學
地點：雁棲湖校區教1-215
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