Resurgence in Lorentzian quantum cosmology: no-boundary saddles and resummation of quantum gravity corrections around tunneling saddles

We revisit the path-integral approach to the wave function of the universe by utilizing Lefschetz thimble analyses and resurgence theory. The traditional Euclidean path-integral of gravity has the notorious ambiguity of the direction of Wick rotation. In contrast, the Lorentzian method can be formulated concretely with the Picard-Lefschetz theory. Yet, a challenge remains: the physical parameter space lies on a Stokes line, meaning that the Lefschetz-thimble structure is still unclear. Through complex deformations, we resolve this issue by uniquely identifying the thimble structure. This leads to the tunneling wave function, as opposed to the no-boundary wave function, offering a more rigorous proof of the previous results. Further exploring the parameter space, we discover rich structures: the ambiguity of the Borel resummation of perturbative series around the tunneling saddle points is exactly cancelled by the ambiguity of the contributions from no-boundary saddle points. This indicates that resurgence works also in quantum cosmology, particularly in the minisuperspace model.Comment: 14 pages, 7 figure

Adult T-Cell Leukemia/Lymphoma with Gastric Lesion

A case of adult T-cell leukemia/lymphoma with a gastric tumor is presented. The patient was a 72-year-old woman who had been admitted to our hospital because of epigastric pain. Upper gastrointestinal endoscopy disclosed polypoid region in the antrum of the stomach. Specimens taken from this region revealed malignant lymphoma. Although the patient was serologically positive for human T-cell leukemia virus type I antibody. A chest X-ray, abdominal ultrasonography, and whole body computed tomography revealed no lymphadenopathy. We diagnosed her to have primary gastric malignant lymphoma and thus performed a total gastrectomy with regional lymph node excision and a splenectomy. Both histological and immunohistochemical studies of the resected specimen showed the lymphoma to be a diffuse pleomorphic type with a T cell phenotype. A radical surgical resection could be performed. At nine months postoperatively, she was again admitted to our hospital because of abdominal pain. Both ultrasonography and computed tomography revealed lymph node swelling around the surrounding the para aorta. She was treated with systematic chemotherapy. Unfortunately, she died at one year after the operation

Large Benign Polyp of the Extrahepatic Bile Duct (Mimicking Bile Duct Cancer)

An 85-year-old woman was admitted because of epigastric pain. The endoscopic examination showed the presence of duodenal ulcer. Abdominal ultrasonography and computed tomography revealed a dilatation of the common bile duct, but no apparent stones were seen in the biliary tract including the gall bladder. In addition, endoscopic retrograde cholangiography showed a filling defect, 20x30 mm in size, in the extrahepatic bile duct. The laboratory data and serum tumor makers were within normal limits. Carcinoma of the extrahepatic bile duct was tentatively made. At operation, an exploration using cholangioscopy and ultrasonography failed to reveal any malignancy. She underwent a local excision of the biliary tumor. Histological examination of the resected specimen showed a benign papillary adenoma. This case is herein reported because of rarity of the disease, which was incidentally found

A STUDY ON POSTOPERATIVE MORTALITY AND MORBIDITY AFTER PANCREATODUODENECTOMY

The early postoperative results of pancreatoduodenectomy performed in our institute during the last 20 years were reviewed, dividing the cases into two groups, from 1970 to 1979 and from 1980 to 1989. Among a total of 136 pancreatoduodenctomies, 52 were performed in the earlier decade and 84 in the latter decade. Patients were significantly older in the latter than in the earlier decade. In the earlier decade, postoperative complications developed in 28.8% of the patients with a 19.2% overall mortality rate. In the latter decade, the complications occurred in 27.4% with a 6.0% mortality rate. There was a significant decrease in overall mortality rate between the two decades. The most common complication was the dehiscence of pancreatojejunostmy, but life-threatening major leakage was decreased. It was considered that recent improvements in surgical techniques and intraoperative and perioperative management contributed to the improvement of the results of this procedure. However, continuing efforts are needed to reduce the morbidity rate, which remains high